Roasted Butternut Squash Sandwich with Caramelized Onions and Pesto

This roasted butternut squash sandwich with caramelized onion and pesto is a super easy recipe to make when winter squash is abundant. It is excellent for a healthy meatless lunch or dinner.

This recipe is my version of the sandwich I used to love at a store near my old workplace. Nowadays, I enjoy making it at home (besides this pumpkin soup and pumpkin fritters with salted egg yolk sauce) when winter squash is in season. It is easy to make, and there are several ways to customize it to your liking.

Ingredients

Here are the main ingredients you’ll need for this recipe:

• butternut squash: I haven’t tried making this sandwich with other types of cooking squash. If you try other squashes, please feel free to comment.
• bread: I often use ciabatta. Baguette, hoagie roll or your other favorite bread for sandwich will work too.
• caramelized onions: these are sliced onions that are cooked on the stove gradually until caramelized, soft and sweet.
• pesto: it adds a pleasant herby fragrance to the sandwich. If you want to keep the sandwich vegetarian/vegan, please use vegetarian/vegan pesto.

Optional Add-ins

You can customize this roasted butternut squash sandwich by adding more filling, for example:

• cheese
• arugula
• other roasted veggies such as zucchini or eggplant

Main Cooking Steps

The recipe has two main steps, which are not quick but fairly straightforward.

1️⃣ Roasting the butternut squash: simply slice the squash thinly, and toss with salt, pepper and oil. You can also add some dried herbs if desired. Then bake in the oven until tender.

2️⃣ Caramelizing the onions: this step does require some time and patience. You will need to cook the onions gradually to deepen the color, flavor and sweetness. 

I like to start with cooking the onions in olive oil over medium heat, and then reduce the heat as needed. Halfway through the process, time to add some butter and continue to cook until your desired level of caramelization is reached.

I don’t think it is necessary to cook them very dark. I prefer a lighter level of caramelization which ensures no unpleasant bitterness as well as saves up some cooking time.

Once these two components are ready, you can assemble the sandwich pretty quickly. I like to have the bread toasted for some extra crunch. I look forward to hearing how you make this roasted butternut squash sandwich recipe.

Related Recipes

⭐️ I’d love to hear what you think about the dish, so please feel free to leave a comment and a rating if you have tried it. New recipes are added every week so let’s connect on Facebook, Youtube, Pinterest and Instagram for the latest updates. You can find my collection of Vietnamese recipes here.

Roasted Butternut Squash Sandwich with Caramelized Onions and Pesto

This roasted butternut squash sandwich with caramelized onion and pesto is a super easy recipe to make when winter squash is abundant. It is excellent for a meatless lunch or dinner.

5 from 3 votes

Print Pin Rate

Course: Appetizer, Main Dish

Cuisine: American

Keyword: butternut squash sandwich

Prep Time: 10 minutes

Cook Time: 50 minutes

Total Time: 1 hour

Servings: 2 people

Calories: 332kcal

Author: Sophie

Ingredients

US Customary – Grams

• ▢ 18 oz peeled and thinly sliced butternut squash (no more than ¼ inch thick)
• ▢ 1/2 plus 1/8 teaspoon salt, divided
• ▢ 3/8 teaspoon black pepper, divided
• ▢ olive oil
• ▢ 2 yellow onions, peeled and thinly sliced (about 10.5 oz/300g)
• ▢ 1 tablespoon butter
• ▢ your choice of bread for sandwich
• ▢ 2-4 tablespoons pesto

Instructions

• Preheat the oven to 425°F (220°C). Toss the butternut squash slices with ⅜ teaspoon salt, ¼ teaspoon pepper and 2½ tablespoons olive oil. Arrange them in a single layer on a baking sheet lined with parchment paper.
• Roast the butternut squash in the preheated oven for about 20 minutes, then flip and roast until tender and browned to your liking, about 10 minutes more.
• Place a skillet over medium heat and add oil to coat the bottom. Once the oil is hot, add the onion slices. Let them cook, stirring occasionally for about 15 minutes. Reduce the heat if needed.
• Add the remaining salt and pepper to the onions, stir and cook for another 5 minutes. Increase the heat back to medium, then add butter. Continue to stir and cook for 20-30 minutes more until they are browned, soft and sweet. A light degree of caramelization will also work.
• Toast the bread. Spread pesto on each cut side, then add the roasted butternut squash slices and caramelized onions. See Notes for optional add-ins. Serve right away.

Notes

You can customize this roasted butternut squash sandwich by adding more filling, such as:

• cheese
• arugula
• other roasted veggies such as zucchini or eggplant

You can use ciabatta, hoagie rolls, baguettes or your other favorite bread for sandwich.

Nutrition

Calories: 332kcal | Carbohydrates: 55g | Protein: 7g | Fat: 12g | Saturated Fat: 5g | Polyunsaturated Fat: 0.3g | Monounsaturated Fat: 2g | Trans Fat: 0.2g | Cholesterol: 16mg | Sodium: 1064mg | Potassium: 1066mg | Fiber: 8g | Sugar: 11g | Vitamin A: 27604IU | Vitamin C: 62mg | Calcium: 176mg | Iron: 2mg

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