Name: Squash Sandwich with Simple Cashew Mozzarella and Caramelized Balsamic Onions Recipe
Prep time: 15 min
Cook time: 30 min
Total time: 45 min
Cuisine: Vegetarian American
Ingredients: ½ butternut squash, sliced thin; ½ tbsp coarse black pepper; ½ tsp granulated garlic; ½ tsp sea salt; 1 tbsp olive oil; 1 medium onion, sliced thin; ½ tbsp olive oil; 1 tbsp balsamic vinegar; ½ tsp cane sugar; ½ cup raw cashews (soaked for 15 min in boiling water); 1 cup fresh cool water; 3 ½ tbsp tapioca starch (or tapioca flour); 1 tbsp lemon juice; ½ tsp sea salt; ½ tsp garlic powder; 2 tbsp nutritional yeast; 8 slices bread of your choice; cranberry sauce (optional, use up your leftovers!)

Jump to Recipe· 3.8 from 11 reviews

If you’re looking to impress your taste buds with a wholesome, mouthwatering delight, this Squash Sandwich with Simple Cashew Mozzarella and Caramelized Balsamic Onions Recipe is going to steal your heart. Imagine tender roasted butternut squash layered with a luscious, creamy cashew-based mozzarella and topped off with sweet, tangy caramelized onions that bring every bite to life. With the perfect harmony of textures and flavors, this sandwich feels indulgent yet nourishing, making it an absolute favorite for any season or occasion.

Ingredients You'll Need

A long yellow sliced fruit or vegetable, neatly layered in a row on a white cloth placed on a white marbled surface. To the left, a white bowl holds thinly sliced white onion rings. Around the cloth, scattered light brown nuts add texture. Three small clear glass bowls contain different ingredients: one with a light powder, another dark liquid, and another with a yellow grainy substance. A metal spoon with a white handle rests near these bowls. The background includes parts of dark pans with brown food inside, all set on the white marbled surface. Photo taken with an iphone --ar 4:5 --v 7

These ingredients may seem simple, but they are essential building blocks that come together to create an explosion of taste and texture. Each ingredient plays its own role — from the creamy cashew mozzarella providing melt-in-your-mouth richness to the vibrantly spiced roasted squash giving warmth and color.

½ butternut squash, sliced thin: The star of our sandwich, roasted to tender perfection for sweet and earthy flavor.
½ tablespoon coarse black pepper: Adds a spicy kick that contrasts beautifully with the squash’s natural sweetness.
½ teaspoon granulated garlic: Infuses warmth and depth throughout the squash slices.
½ teaspoon sea salt: Enhances all flavors, balancing sweetness and spice flawlessly.
1 tablespoon olive oil: Helps coat and roast the squash for a golden, crispy edge.
1 medium onion, sliced thin: Transforms into luscious caramelized balsamic onions that elevate every bite.
½ tablespoon olive oil: For gently sautéing onions to softness and golden caramelization.
1 tablespoon balsamic vinegar: Brings tangy sweetness to the onions, enhancing their richness.
½ teaspoon cane sugar: Balances the acidity with a gentle caramel flavor.
½ cup raw cashews (soaked for 15 min in boiling water): The creamy base for our simple cashew mozzarella that’s both dairy-free and indulgent.
1 cup fresh cool water: Keeps the cashew cheese smooth and luscious after blending.
3 ½ tablespoon tapioca starch (or tapioca flour): Adds the stretchy, melty texture that mimics traditional mozzarella cheese.
1 tablespoon lemon juice: Brightens the cashew mozzarella with a fresh, tangy punch.
½ teaspoon sea salt: Rounds out the flavor in the cashew cheese.
½ teaspoon garlic powder: Adds subtle savory notes to the mozzarella.
2 tablespoon nutritional yeast: Gives that unmistakable cheesy, nutty flavor that’s key to our cashew mozzarella.
8 slices bread of your choice: The sturdy canvas to hold all the delicious layers together.
Cranberry sauce (optional): A sweet-tart drizzle that adds vibrant color and an unexpected punch.

How to Make Squash Sandwich with Simple Cashew Mozzarella and Caramelized Balsamic Onions Recipe

Step 1: Prepare and Roast the Squash

Start by preheating your oven to 425 degrees F and lining two baking sheets with parchment paper or silicone mats for easy cleanup. Peel, deseed, and thinly slice half a butternut squash. The thickness matters: about ¼ inch works best to get tender and slightly crispy slices. Toss each slice in olive oil and then coat them with a mix of black pepper, granulated garlic, and sea salt. Lay them out evenly on your baking sheets and roast for 15 to 20 minutes until the edges are golden and the center is soft. This step brings out the squash’s natural sweetness and creates a wonderful texture contrast.

Step 2: Make the Caramelized Balsamic Onions

While your squash roasts, thinly slice one medium onion. Heat olive oil in a skillet over medium heat, then add the onions and stir gently until they start to sweat and soften—this takes about 5 minutes. Add the balsamic vinegar and cane sugar, stirring to coat the onions evenly. Let them cook for another 5 to 10 minutes until deeply caramelized and richly fragrant. The balsamic vinegar adds a tangy counterpoint to the sweetness of the onions while intensifying their natural flavor.

Step 3: Whip Up the Simple Cashew Mozzarella

This is the magic that pulls the sandwich together! Drain the soaked cashews and add them to a blender with fresh water, tapioca starch, lemon juice, sea salt, garlic powder, and nutritional yeast. Blend until perfectly smooth. Pour this creamy mixture into a saucepan over medium-low heat, stirring almost constantly until it thickens and becomes stretchy—about 5 to 8 minutes. This cashew mozzarella has an incredible melt and texture that feels indulgent without the dairy.

Step 4: Assemble Your Sandwich

Toast your favorite bread slices to add crispiness and structure. Spread the warm cashew mozzarella generously on both pieces, then layer on the roasted squash slices. Spoon a hearty amount of the caramelized balsamic onions on top, and if you’re feeling adventurous, add a drizzle of cranberry sauce for a sweet and tangy twist. Close the sandwich, press it lightly, and enjoy this delightful medley while it’s hot and melty.

How to Serve Squash Sandwich with Simple Cashew Mozzarella and Caramelized Balsamic Onions Recipe

The image shows a sandwich on a white plate placed on a white marbled surface. The sandwich has two slices of seeded brown bread with a crispy, toasted texture. Inside, there is a layer of melted cheese that looks smooth and creamy, topped with cooked mushrooms that have a dark brown, slightly glossy look. There is a bright red layer of jam or sauce spilling slightly from the sandwich. Around the plate, there are scattered cashew nuts, a slice of yellow pumpkin with black edges on a white plate, and a spoon with thick white spread on the surface nearby. In the background, there is a jar filled with more of the red jam and a cast iron pan with a wooden spatula. Photo taken with an iphone --ar 4:5 --v 7

Garnishes

To elevate your sandwich further, consider fresh garnishes like fragrant basil leaves or a sprinkle of cracked black pepper. A dash of chili flakes can also add an exciting kick that contrasts wonderfully with the creamy and sweet layers. Garnishes not only boost flavor but add vibrant color and texture, making your sandwich visually and gastronomically irresistible.

Side Dishes

This sandwich pairs perfectly with crisp green salads dressed in zesty lemon vinaigrette or a bowl of hearty vegetable soup. For something a bit more indulgent, baked sweet potato fries or a tangy coleslaw can round out your meal with complementary textures and flavors. Keep the sides light and fresh to let your sandwich shine as the star of the table.

Creative Ways to Present

Looking to impress guests or make this sandwich a fun centerpiece? Cut it into halves or thirds and skewer with rosemary sprigs or toothpicks for easy sharing. Layer the sandwiches open-faced on rustic wooden boards accompanied by small bowls of cranberry sauce and extra caramelized onions. Wrapping a sandwich tightly in parchment paper can give it a charming, casual look perfect for picnics or casual lunches.

Make Ahead and Storage

Storing Leftovers

If you find yourself with leftover squash sandwich components, store them separately in airtight containers. The roasted squash and caramelized onions will last for about 3 to 4 days in the refrigerator, while the cashew mozzarella remains best when consumed within two days due to its delicate texture. Keeping the bread separate prevents sogginess when you’re ready to enjoy leftovers.

Freezing

The cashew mozzarella can be frozen in small portions for up to three months. Thaw it in the refrigerator overnight and gently reheat to restore its stretchy texture. Roasted squash and onions freeze well but tend to get softer upon thawing, so they’re best enjoyed fresh or refrigerated. Bread generally does not freeze well when toasted, so keep it fresh or freeze untoasted slices instead.

Reheating

To reheat your assembled sandwich or its parts, use a skillet over low heat to warm until the cashew mozzarella melts and the sandwich is heated through without drying out. Alternatively, a toaster oven can bring back a nice crispness to the bread. Avoid microwaving as it tends to alter the texture of the mozzarella and can make the bread chewy.

FAQs

Can I use other types of squash for this recipe?

Absolutely! While butternut squash is ideal for its sweetness and texture, you can experiment with delicata or kabocha squash. Just adjust the roasting time depending on firmness and slice thickness.

Is it necessary to soak the cashews before making mozzarella?

Yes, soaking softens the cashews and makes blending smooth easier, resulting in a creamy cheese. Quick soaking in boiling water for 15 minutes works well if you're short on time.

Can I make this sandwich gluten-free?

Definitely! Simply swap the bread for your favorite gluten-free alternative, and all ingredients used are naturally gluten-free, making this sandwich suitable for many dietary needs.

How long do the caramelized onions keep in the fridge?

Stored in an airtight container, caramelized balsamic onions last up to five days refrigerated. Their flavor even intensifies after a day, making them perfect for prepping ahead.

What can I substitute for tapioca starch?

Tapioca starch is key for that stretchy mozzarella texture. If unavailable, you can try arrowroot powder, but the stretchiness might be slightly less pronounced. Experimenting with small batches helps find what works best for you.

Final Thoughts

This Squash Sandwich with Simple Cashew Mozzarella and Caramelized Balsamic Onions Recipe is truly a celebration of flavors and textures that’s both comforting and innovative. It’s a perfect way to enjoy seasonal produce in a delicious, plant-based way that feels special every time. I encourage you to give this recipe a try, gather your ingredients, and treat yourself and your loved ones to a sandwich experience that’s bursting with warmth, creaminess, and satisfying layers of caramelized goodness.

Squash Sandwich with Simple Cashew Mozzarella and Caramelized Balsamic Onions Recipe

Ingredients You'll Need