Heat fat in Dutch oven over medium-high heat; add pork cubes and brown evenly on all sides. Add onions and garlic to pan; cook and stir until onions are tender, about 10 minutes.

Stir in remaining ingredients and bring all to a boil. Lower heat to a simmer, cover and simmer until pork is very tender and liquid is slightly thickened. Serve immediately over hot cooked rice, if desired. Garnish with fresh cilantro sprigs.