chicken spaghetti casserole

Ingredients

• 8 ounces uncooked spaghetti,broken into 3-inch pieces
• 3 cups cubed cooked chicken
• 1 can condensed cream of chick soup,undiluted
• 1 - medum onion,chped
• 1 cup milk
• 1 cup shredded sharp cheddar cheese divided
• 1 cup shredded swiss cese,divided
• 1 can mushroom stems and drained
• 1/2 cup chopped roasted sweet red peppers
• 3 tablespoons maonnaise
• 1 1/2 teaspoons mccormick's montreal steak seasoning
• 1/2 teaspoon dried basil