Parisian Ham-and-Cheese Sandwich -- Croque Monsieur

Place butter and flour in a 1-cup glass measure (microwave-safe). Microwave, uncovered, on HIGH, just until butter is melted, about 30 seconds. Remove and stir well to incorporate flour. Microwave for another 15 seconds or until mixture is bubbling quickly. Remove and stir in milk and broth, stirring well until completely incorporated and any lumps are gone. Microwave mixture for 30-second intervals, stirring well between each interval, until mixture is steaming and has a consistency between thick cream and warm pudding. This will take up to 1½ to 2 minutes. Remove sauce from microwave and use as needed. Cover any leftovers tightly, and refrigerate for up to 1 week. Reheat in the microwave and adjust consistency with additional milk, 1 teaspoon at a time. Makes ½ cup. Cook's note: You can also use whole milk, half-and-half or cream. @Recipe nutrition:Nutrition values per tablespoon: 20 calories, 1.6 g fat (1 g saturated), 1 g carbohydrates, 0 fiber, trace amount protein, 4 mg cholesterol, 118 mg sodium.