Process chicken in a food processor until consistency of ground beef; spoon into a large bowl.
Add egg and next 6 ingredients to ground chicken in bowl; stir until blended. Shape chicken mixture into 8 patties (about 6 ounces each). Chill 30 minutes or until firm.
Cook chicken patties, in batches, in a lightly greased nonstick skillet over medium-high heat 5 to 7 minutes on each side or until done. Top each patty with 1 cheese slice. Cover and cook 1 minute or until cheese melts.
Top bottom halves of buns with tomato slices. Spread Lemon Mayonnaise evenly on tomato slices. Top with chicken patties and lettuce, and cover with tops of buns.