1 med. head cauliflower
2 c. cubed cooked ham
1 (3 oz.) can sliced mushrooms,
drained
4 tbsp. butter
1/3 c. flour
1 c. milk
1 c. cubed sharp American cheese
1/2 c. dairy sour cream
1 c. soft bread crumbs
2 tbsp. melted butter

Break cauliflower into buds, cook in boiling water until tender (10-20 minutes); drain. In medium saucepan, melt 4 tablespoons butter, stir in flour and milk for white sauce. Cook and stir until mixture thickens, and bubbles. Add cheese and sour cream to sauce, stir until cheese melts. Combine cauliflower, ham and mushrooms with sauce, pour into 2 quart casserole dish. Combine bread crumbs and 2 tablespoons melted butter, sprinkle over top. Bake uncovered for 40 minutes (or until hot and bubbly) at 350 degrees.
 

Source: http://www.nancys-kitchen.com