1 (5 1/2 oz.) pkg. au gratin potatoes
4 c. boiling water
1 tsp. salt
1 tbsp. butter, melted
1/4 c. grated Parmesan cheese
1 (10 oz.) pkg. frozen, chopped broccoli, thawed
1/2 c. sliced celery
1/2 c. chopped onion
2 tbsp. butter
1 1/2 c. milk
1/4 tsp. dry mustard
2 1/2 c. cut up cooked turkey or chicken
1/2 c. shredded Cheddar cheese

Grease a 9 x 9 x 2 inch baking pan. Put potatoes in a 2 1/2 quart bowl; pour in boiling water. Stir in salt. Let stand, uncovered, for 15 minutes. Drain. Toss potatoes with the melted butter and Parmesan cheese. Press potato mixture in pan; top with broccoli. Melt the 2 tablespoons butter; add celery and onion. Cook and stir until tender. Stir in packet of sauce mix, milk, and mustard. Heat to boiling, stirring constantly. Reduce heat; simmer, uncovered, until sauce thickens (about 5 minutes). Stir in turkey. Pour mixture over broccoli. Bake, uncovered, 25 minutes at 375 degrees. Sprinkle with Cheddar cheese; return to oven until cheese melts, about 5 minutes. Let stand 5 minutes before serving.