PAT pork cubes dry with paper towels.
In a large Dutch oven, HEAT oil over medium-high heat until very hot; ADD cubes; STIR-FRY until browned; REMOVE meat; SET aside.
REDUCE heat to medium; ADD onion; COOK until tender, about 10 minutes.
STIR in garlic, chili powder, cumin, cinnamon, cayenne and cloves; COOK 1 minute.
RETURN pork to Dutch oven; ADD tomatoes with juice, vinegar, salt, oregano and bay leaf; over high heat, HEAT to boiling, breaking up tomatoes.
REDUCE heat; COVER; SIMMER until pork is very tender, about 2 hours.
DISCARD bay leaf; SKIM and DISCARD fat.
SPRINKLE dish with cilantro; SERVE over warm tortillas if desired.
Per Serving (excluding unknown items): 335 Calories; 23g Fat (61.6% calories from fat); 22g Protein; 11g Carbohydrate; 3g Dietary Fiber; 81mg Cholesterol; 392mg Sodium. Exchanges: 0 Grain(Starch); 3 Lean Meat; 1 1/2 Vegetable; 3 Fat; 0 Other Carbohydrates.