Yield: serves 4
Preheat oven to 400° F. On a parchment lined baking sheet, spread out butternut squash. Drizzle with 1-2 tablespoons of olive oil. Season with salt and pepper. Toss to combine. Bake for 30-40 minutes until squash is soft and can be easily pierced with a fork or knife. Set aside.
Bring a large pot of salted water to a boil. Cook spaghetti to al dente according to package details. When draining pasta, reserve a cup of pasta water.
In a large nonstick skillet, melt butter over medium heat. Once butter is melted, continue to cook over medium low heat until butter has browned and is fragrant (should smell nutty).
Add minced garlic (I like to smash mine using a mortar and pestle) and sliced onions. Cook until onions are almost translucent. Add baby kale in two additions. Cook until kale begins to wilt. Remove from heat.
Add pecorino romano, parmesan cheese, and roasted butternut squash. Toss to combine. Season with salt and pepper to taste. Add cooked spaghetti and toss to coat pasta. Add 1/4 cup of reserved pasta water at a time until pasta is well coated with sauce. (I ended using 1/2 cup of pasta water).
Serve immediately with sliced chives and/or more cheese, if desired.