4 tablespoons all-purpose flour
1 1/2 cups milk
1 (16 ounce) package frozen peas and onions, thawed
salt and pepper to taste
In a large skillet over low heat, stir together the butter and flour. Cook until flour is evenly coated. Over medium heat, stir in approximately 1/2 cup of milk at a time until thick. Add the peas and onions and cook until hot. Season with salt and pepper.