1 bag frozen broccoli-cauliflower mix, cooked
1/2 c. chopped onion
1 tbsp. butter
1 can mushroom soup (undiluted)
1/2 tsp. dry mustard
Salt to taste
2 c. shredded cheddar cheese
1 can fried onion rings

Saute onion in butter. Stir in soup, mustard and salt. In casserole dish place 1/2 of broccoli and cauliflower, 1/2 of cheese, 1/2 of soup mixture; repeat. Bake at 350 degrees for 20 minutes (or heat through in microwave). Top with onions. Bake 5 more minutes.