Immerse entire corned beef in water for four hours, drain, and rinse. Cut meat into coarse cubes and place in a pot. Add one whole onion stuck with cloves. Quarter the other onion, add to pot, and cover with cold, fresh water. Bring to a boil, reduce heat, and simmer for at least two hours or until meat is fall-apart tender. Meanwhile, shred cabbage, boil until tender, then set aside. When meat is done, drain. Reserve at least one cup of stock with quartered onion. Discard the whole onion with cloves. In another pot, saute the chopped leek or scallions, garlic, and chili peppers in olive oil to release flavors. Add stock, salt, and pepper. Bring to a simmer and stir until heated through. Pour over cabbage. Arrange beef on top of cabbage and serve with boiled potatoes, yams, or rice.