PREPARATION:
- Combine chicken, eggs, onion, bread crumbs, parsley, Parmesan cheese, salt, baking soda, pepper and oregano in large bowl; mix well. Shape chicken mixture into 4 patties.
- Heat butter and oil in large skillet over medium-low heat until butter melts; add patties. Cook until patties are no longer pink in center, 4 to 5 minutes on each side. Place 1 slice cheese on top of each patty. Cover skillet; cook until cheese melts, about 1 minute.
- Spread each bun with 1 tablespoon mayonnaise; arrange 1 lettuce leaf on bottom half of each bun. Top with chicken patty, tomato slices and top half of bun. Serve hot.
