Cheese Sauce

2 Tbsp butter
2 Tbsp flour
1 cup milk
1/2 tsp salt
1/2 tsp dry mustard
1 cup sharp cheddar cheese

Melt butter in 1 quart glass bowl in microwave. Add flour and blend to a smooth paste. Wisk in milk. Cook uncovered in microwave for about 3-4 minutes, wisking after every minute. Once thickened, add salt and dry mustard. Blend in cheese.