1. Preheat grill to medium-high heat. Sprinkle patties with salt and pepper.
2. Grill patties, covered, on a grill rack rubbed with 2 Tbsp oil 5 to 6 minutes per side or until no longer pink.
3. Cook onion in 2 Tbsp hot oil in a skillet over medium heat 2 to 3 minutes or until tender; stir in tomatoes, artichokes, roasted peppers, and olives.