Grilled Greek Chicken Sandwiches

Heat a grill pan or a very large nonstick skillet over medium heat. Lightly coat red onion and pepper with nonstick spray; add to hot grill pan or skillet. Cook for 6 to 8 minutes or until tender, turning once. Remove from skillet. Lightly coat chicken with nonstick spray; add to hot grill pan or skillet. Cook for 3 to 5 minutes or until no longer pink, turning once. Remove chicken from skillet; if desired, using two forks, pull chicken apart into coarse shreds. Cut the pepper quarters into bite-size strips.

To assemble sandwiches, spread cut sides of the sandwich rounds with pesto. Sprinkle bottoms of sandwich rounds with olives. Place grilled onion slices on olives. Top with pepper strips. Place chicken over peppers. Sprinkle with mozzarella cheese and feta cheese. Top with sandwich round tops, cut sides down. Lightly coat outsides of sandwiches with nonstick spray.

Place the grill pan or skillet over medium-low heat. Add sandwiches, in batches if necessary. Place a heavy skillet on sandwiches. Cook over medium-low heat for 3 to 4 minutes or until sandwich bottoms are toasted. Carefully remove top skillet (skillet may be hot). Turn sandwiches over; top again with the skillet. Cook for 3 to 4 minutes more or until bread is toasted and cheese is melted.