Place Peanut Butter, Water, Sugar And Half And Half In A 2 Quart Glass Measure. Cover With Vented Plastic Wrap. Stirring Midway Through Cooking, Microwave On High For 8 Minutes Or Until Mixture Begins To Boil. Whisk Until Well Combined. Stir In Cornstarch Mixture And Microwave On High For 8 Minutes Or Until Thickened. Ladle Into Bowls And Garnish Servings With Peanuts And Mint Leaves. Makes 6 Servings.