Cheddar Cheese Sauce:
2 tablespoons margarine (I used Smart Balance, Original)
3 tablespoons all-purpose flour
1/8 teaspoon dry mustard
1/4 teaspoon salt
1/4 teaspoon ground black pepper
1 1/3 cups whole milk or half-and-half (or combination)
1 (8 oz) block Sharp cheddar cheese, shredded (I used Kraft 2%)
In a heavy 2-qt. non-stick saucepan, melt the margarine over medium heat; whisk in the flour, mustard, salt, pepper, and paprika and cook, whisking constantly, for 1-2 minutes (do not brown). Gradually add the milk, whisking vigorously, until well blended and smooth. Cook and whisk until sauce thickens to desired consistency. Remove from heat and stir in the shredded cheese until melted.
Serve hot over steamed broccoli or cauliflower or a baked potato.