Adding the butter slowly is key. If you dump it all in at once, it can cause the sauce to separate.
Calories: 295kcal | Carbohydrates: 1g | Protein: 2g | Fat: 32g | Saturated Fat: 19g | Polyunsaturated Fat: 2g | Monounsaturated Fat: 9g | Trans Fat: 1g | Cholesterol: 221mg | Sodium: 301mg | Potassium: 27mg | Fiber: 0.01g | Sugar: 0.2g | Vitamin A: 1070IU | Vitamin C: 1mg | Calcium: 26mg | Iron: 0.4mg