Preheat your oven to 375°F (190°C).

Season the chicken breasts liberally with salt and pepper. Heat 2 tablespoons of oil in a skillet over medium heat, then add the chicken. Sauté for about 6–8 minutes per side or until cooked.

Bring a pot of water to a boil and add the cubed butternut squash. Cook for 10–12 minutes until fork-tender. Drain and set aside.

In a large mixing bowl, combine the cooked butternut squash, shredded chicken, diced onion, and minced garlic. Mix gently to combine.

Stir in 1 cup of chicken broth, ½ cup of heavy cream, ¾ cup of shredded cheddar cheese, dried thyme, salt, and pepper into the mixture. Combine until creamy and well blended.

Transfer the mixture into a greased 9x13 inch baking dish, top with remaining cheese and breadcrumbs.

Place the baking dish in the preheated oven and bake for 25–30 minutes until edges are bubbling and the top is golden brown.

Remove your casserole from the oven and cool for about 5 minutes before serving.