Company chicken casserole features tender chicken in an elegant cream sauce that's fancy enough for guests yet easy enough for weeknights. This high protein, family-friendly chicken dish always impresses.
Preheat oven to 375°F, and lightly butter a 9x13-inch casserole dish for even baking.
Cut chicken breasts into bite-sized pieces; sauté in 2 tbsp butter over medium-high heat until just cooked through and lightly golden, about 7 minutes. Remove and set aside.
Add remaining butter to skillet, then sauté mushrooms for 5 minutes until softened and moisture evaporates, maintaining medium heat for depth of flavor.
Stir in flour, then gradually whisk in chicken broth and heavy cream. Simmer, stirring constantly, until thickened (3–4 minutes). Season with salt, pepper, and garlic powder for balanced taste.
Combine chicken, mushrooms, cooked egg noodles, peas, and cheddar in a mixing bowl. Pour the cream sauce over, mix gently, and transfer to casserole dish.
Bake casserole uncovered for 25–30 minutes or until bubbly and lightly golden on top. Let rest 5 minutes before serving for optimal texture.