Ingredients:
- 2 large chayote squash (approximately 1.5 lbs / 680g), peeled, halved, and thinly sliced
- 1 medium yellow onion, finely chopped (about 1 cup / 150g)
- 3 cloves garlic, minced
- 4 tablespoons (57g) unsalted butter
- 4 tablespoons (30g) all-purpose flour
- 3 cups (720ml) whole milk
- 1 teaspoon smoked paprika
- 1/2 teaspoon ground nutmeg
- 1/4 teaspoon cayenne pepper (optional)
- 1 1/2 cups (approximately 170g) shredded Gruyere cheese, divided
- 1 cup (approximately 113g) shredded sharp cheddar cheese, divided
- Salt and freshly ground black pepper to taste
- 2 tablespoons breadcrumbs (plain or panko)
- 1 tablespoon olive oil
Instructions:
- Peel, halve, and thinly slice the chayote using a mandoline or sharp knife. Chop the onion.
- Heat olive oil in a large saucepan over medium heat. Add the onion and cook until softened and translucent. Add garlic and cook until fragrant.
- Melt butter in the same saucepan. Whisk in flour and cook for 1-2 minutes to form a roux. Gradually whisk in milk, ensuring no lumps form.
- Bring the sauce to a simmer, stirring constantly. Reduce heat and simmer for 5-7 minutes, or until thickened. Stir in smoked paprika, nutmeg, cayenne pepper (if using), salt, and pepper. Remove from heat.
- Stir in 1 cup Gruyere cheese and 1/2 cup Cheddar cheese into the sauce until melted and smooth.
- Preheat oven to 375°F (190°C). Lightly grease the baking dish. Arrange a layer of chayote slices on the bottom of the dish, followed by a layer of the cheesy sauce. Repeat layers until all ingredients are used, finishing with a layer of sauce.
- Sprinkle the remaining Gruyere and Cheddar cheese over the top of the gratin. Sprinkle breadcrumbs over the top.
- Bake for 30-35 minutes, or until golden brown and bubbly.
- Let cool for 10 minutes before serving.