Prepare Knorr® Italian Sides™ - Alfredo with water, milk and 1 Tbsp. margarine according to package directions.
Meanwhile, melt remaining margarine in largre skillet over medium heat and cook onion and garlic, stirring occasionally, until soft, about 2 minutes. Stir in prosciutto and peas; heat through. Toss with hot Pasta sides. Sprinkle, if desired, with chopped fresh basil and cracked black pepper.