Melt butter in a large skillet over medium heat. Add mushrooms and next 4 ingredients. Cook, stirring constantly for 5 mins or until tender. Add spaghetti squash and next 6 ingredients, cook 4 mins, stirring constantly. Stir in sour cream, cook, stirring constantly, just until thoroughly heated. Remove from heat. Sprinkle with cheese. Cover and let stand for 1 minute. To bake, prepare mixture according to directions and spoon into a lightly greased 1.5 quart casserole dish. Cover and bake at 350 for 20-25 mins. Posted to MM-Recipes Digest by Pat Connors on Feb 08, 1998