Place chicken breasts in baking dish or sealed plastic bag with dressing and marinate for at least 1 hour (or overnight).
Preheat barbeque to medium-high or 400 degrees.
Bring a large pot of salted water to boil.
Add pasta and cook until al dente, (10-12 min), then drain.
Grill chicken breasts on the bbq until juices run clear (approx seven minutes on each side).
Once cool enough to handle, slice into strips or chunks.
Meanwhile, heat oil in a large nonstick pan at medium-high and add onion and garlic.
Cook, stirring occasionally until softened.
Stir in tomatoes and cook a few more minutes.
Add onions, garlic, peas, tomato, feta and chicken to the pasta (while hot).
Season with salt and freshly ground pepper.
Toss in fresh mint and lemon zest just before serving.
Finish each plate with a little drizzle of olive oil and crumbled feta.