Tuna Noodle Casserole

Name: Tuna Noodle Casserole
Ingredients: 6 ounces dried curly egg noodles; 1 medium onion finely chopped; 2 tablespoons butter; 8 ozpackage sliced mushrooms; 2 celery stalks finely chopped; 1 teaspoon salt; 1 cup water; 2 chicken bouillon cubes; 1 cup whole milk; 2 tablespoons cornstarch; 8 ozpackage shredded medium Cheddar cheese divided; 3/4 cup frozen peas; 2 (5-oz) cans solid white albacore tuna in water drained; 1/2 teaspoon pepper; 1 cup potato chips gently crushed into smaller pieces