Cut squash in hjalf, discard seeds. Place cut side down in a 15 inches x 10 in x 1 in baking pan. Add 1/2 inch hot water. Bake, uncovered at 350 degrees for 45 minutes.
Drain water from pan, turn swuash cut side up. Bake 10 - 15 minutes longer or until tendr. Scoop out pulp, mash and set aside.
In a large skillet, saute onion in buter until tender. Stir in croutons, salt, poultry seasoning and pepper. Cook 2-3 minutes longer or until croutons are toasted. Stir in squash, turkey and brorh, heat through.
Transfer to a greased 1 1/2 quart baking dish. Bake , uncovered, at 350 degrees for 20 minutes. Sprinkle with cheese. Bake 5 - 10 minutes longer or until edges are bubbly and cheese is melted.