Preheat your oven to 400°F (200°C). Spread cubed butternut squash on a baking sheet, drizzle with olive oil, and toss with chopped sage, salt, and pepper. Roast until tender and slightly caramelized, about 25-30 minutes, filling the kitchen with a sweet, nutty aroma.
While the squash roasts, prepare the breadcrumb topping by mixing breadcrumbs with melted butter and a pinch of salt. Spread this mixture evenly in a small dish and set aside. This will turn golden and crispy during baking.
Once the squash is roasted and soft, remove it from the oven and reduce the oven temperature to 375°F (190°C). In a large mixing bowl, combine the roasted squash, cooked quinoa or rice if using, and shredded cheese. Mix gently until well combined—this creates a creamy, layered filling.
Transfer the squash mixture into a greased casserole dish, smoothing the top with the back of a spoon to create an even surface. Spread the prepared breadcrumb mixture evenly over the top, pressing lightly to adhere.
Place the casserole in the oven and bake for about 20-25 minutes, or until the topping is golden brown and crispy. The filling should be bubbling around the edges, filling your kitchen with warm autumn scents.
Remove the casserole from the oven and let it rest for a few minutes. This helps the layers set and makes serving easier. The crispy topping contrast with the tender, flavorful squash filling creates a cozy, inviting dish.
