Heat 1 tablespoon of butter or margarine in a medium-size skillet on medium-high heat. Add hash browns, onion and 1 tablespoon water. Saute/steam for 7 minutes or until hash browns begin to brown slightly. Transfer to the bottom of 9x9 casserole dish.

While hash browns are steaming, melt 2 tablespoons butter in a small saucepan on medium-high heat. Mix together flour, salt, ground mustard and pepper. Add small amount to pan and whisk into butter. Add small amount of milk. Repeat until flour and milk are mixed into butter. Whisk until lump free. Add 1 cup cheddar and cook mixture until cheese is melted. Remove from heat.

Layer broccoli over hash browns. Layer ham over broccoli. Cover with milk/cheese mixture. Spread 1 cup cheddar on top.

Cover casserole and cook in 350°F oven for 30 minutes. Remove covering and cook for additional 15 minutes or hash browns are tender. Remove from oven.

Serve with salad greens.