In a 16 quart pot combine the tripe and the onions. Add water until pot is about 3/4 full. Cover and cook on low heat for about 2 hours, or until the tripe is tender. Add the hominy, chili powder, and salt and pepper to taste. Cover and cook for another 45 minutes to one hour to incorporate the flavors. Serve with fresh onions, corn tortillas and lemon if desired.
