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.
1๏ธโฃ 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.
2๏ธโฃ 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.
If you need more some fun ideas for what to make with bread, also give these baked shrimp toast and slow cooker pulled pork banh mi a try.
โญ๏ธ Iโd 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 letโs connect onย Facebook,ย Youtube,ย Pinterestย andย Instagramย for the latest updates.ย You can find my collection ofย Vietnamese recipesย here.
Roasted Butternut Squash Sandwich with Caramelized Onions and Pesto
Ingredients
- 18 oz peeled and thinly sliced butternut squash (no more than ยผ 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 425ยฐF (220ยฐC). Toss the butternut squash slices with โ teaspoon salt, ยผ teaspoon pepper and 2ยฝ 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
- cheese
- arugula
- other roasted veggies such as zucchini or eggplant
Really yummy! Especially with her idea of adding the option arugula!
Hi Linda,
Thanks so much for the comment and rating! I’m happy to know you particularly loved it with arugula :)!
Love the flavors here, but next time I’m going to try with my homemade cranberry sauce for a bit of tart flavor!
Hi Bonny,
Thank you so much for the positive feedback and rating! So glad you also love the flavors. Using cranberry sauce sounds like a great idea. I often add dried cranberries whenever I have roasted butternut squash salad. Please feel free to let me know how the sandwich tastes with cranberry sauce :).