(Makes 1 serving)
1/4 small red onion, thinly sliced
1/4 small Granny Smith apple, cored and thinly sliced
1 round focaccia bread (6 inches in diameter), sliced horizontally in half
2 thin slices roasted turkey breast (about 1 1/2 ounces)
1 thin slice Fontina cheese (1/2 ounce)
Spray nonstick skillet with nonstick cooking spray. Heat skillet over high heat. Cook onion 5 to 8 minutes, stirring occasionally, until brown and caramelized. Remove onion from skillet. Cook apple in same skillet about 5 minutes, stirring occasionally, until light brown. Remove from heat.
Heat oven to 325°. Spread mustard on bottom slice focaccia; top with turkey, onion, cheese and apple. Top with remaining slice of focaccia. Place on cookie sheet. Heat in oven 10-15 minutes or until cheese melts and turkey is warm.
To serve, cover sandwich with top half focaccia. Slice sandwich into wedges.