1. Preheat oven to 400 degrees F (200 degrees C).
2. In a 1 1/2 quart casserole dish, combine the ham, beans, corn, cheese, onion and Worcestershire sauce. Mix well and cover.
3. Bake, covered, at 400 degrees F (200 degrees C) for 15 minutes.
4. Meanwhile, in a separate medium bowl, combine the buttermilk baking mix, cornmeal, egg and milk. Mix together well and pour over the ham mixture in the casserole dish.
5. Return to oven and bake, uncovered, for 20 more minutes.