Butter
3 cups (about 16 ounces) cubed (1-inch) leftover turkey
3/4 cup chopped celery
1 (5 ounce) can sliced water chestnuts, drained
1/2 cup chopped red bell pepper
1 1/3 cups mayonnaise
1 tablespoon grated onion
2 tablespoons lemon juice
2 cups (8 ounces) shredded sharp Cheddar cheese, divided
1 cup (4 ounces) shredded mozzarella cheese, divided
1 cup cornflakes, crushed

Preheat oven to 350 degrees F. Lightly coat a 9 x 13-inch baking dish with butter.

In a medium bowl, combine turkey, celery, water chestnuts, red bell pepper, mayonnaise, onion, lemon juice, 1 cup Cheddar cheese, and 1/2 cup mozzarella cheese; mix well. Place the mixture in the baking dish and bake for 25 to 30 minutes, or until heated through.

Meanwhile, in a medium bowl, combine the remaining 1 cup Cheddar cheese, 1/2 cup mozzarella cheese and cornflakes. Sprinkle the cheese mixture over the baked turkey casserole and bake for 5 to 8 minutes, or until the cheese melts.