Cook pasta to al dente according to package directions, then drain--reserving 1 cup cooking water--and return to pot to keep warm (stir in a bit of oil if desired to keep the noodles from sticking together).
Meanwhile, heat grill (inside or outside) to medium, and season chicken with salt and pepper.
Grill chicken 2-3 minutes per side until cooked through; remove from heat and cut into strips.
While chicken cooks, halve tomatoes, cube mozzarella, chop parsley, grate or shred Parmesan (if needed), slice olives (if desired), dice bell pepper, and slice cucumber.
Add the chicken, tomatoes, parsley, butter, and both cheeses to the pasta and toss to combine. If mixture is too dry/thick, add reserved water a little at a time until desired consistency is reached.
In a large bowl, toss together lettuce, olives, bell pepper, and cucumber. Top with your favorite dressing before serving.
Serve pasta with salad and grapes on the side.