Season chicken, if desired with salt and pepper. Melt 1 tablespoon margarine in 12-inch nonstick skillet over medium-high heat and cook chicken, stirring occasionally, 5 minutes or until chicken is thoroughly cooked. Remove chicken and set aside.
Melt remaining 1 tablespoon margarine in same skillet and cook 1/2 of the tomato 2 minutes, stirring occasionally. Add water and milk and bring to a boil. Add Knorr® Pasta Sides™ - Cheesy Bacon Flavor Macaroni and return to a boil. Reduce heat to medium and cook uncovered, stirring occasionally, 10 minutes or until pasta is tender. Stir in chicken.
Spoon onto serving platter. Arrange lettuce around chicken and pasta, then top with remaining chopped tomato. Serve, if desired with Wish-Bone® Ranch Dressing.