Heat lard in a large heavy pot over medium heat. Add onion and cook until softened. Remove from heat.

Add meat, garlic, ground chiles, and cumin to pot. Break up any lumps. Stir in the water and salt. Return to heat. Bring to a boil, then reduce heat and simmer, uncovered, 2½ to 3 hours, stirring occasionally, until the meat is very tender and the flavors are well blended. Add more water if necessary. Taste and adjust seasonings.