1 lb pork shoulder, cooked and shredded 1 lb chicken, cooked and shredded 1 large onion, diced 3 cloves garlic, minced 2 cups diced potatoes 2 cups corn kernels (fresh, frozen, or canned) 2 cups lima beans (fresh, frozen, or canned) 1 can (28 oz) crushed tomatoes 4 cups chicken broth 1/4 cup Worcestershire sauce 1/4 cup apple cider vinegar 1/4 cup ketchup 2 tablespoons brown sugar 1 teaspoon salt 1/2 teaspoon black pepper 1/2 teaspoon red pepper flakes (optional, for heat) 1/4 teaspoon cayenne pepper (optional, for extra heat)