Preheat grill or grill pan to medium-high heat.
Cut romaine hearts lengthwise to make 6 halves; brush cutsides evenly with 1 tablespoon olive oil. Grill romaine, cut sides down, 2 minutes or until lettuce is slightlycharred. Remove from grill, and transfer to serving platter. Brush onion slices with 1⁄2 tablespoon olive oil.
Grill onion 3-4 minutes per side or until golden brownand tender. Brush cut sides of peaches with remaining 1⁄2 tablespoon oliveoil. Grill peaches, cut side down, 3-4 minutes or until goldenbrown and tender. Cut into slices. Top grilled romaine with onions, peaches and feta cheese.
Drizzle with balsamic glaze to serve.