Trim excess fat from meat. Rub cardamom all over meat. Sprinkle generous amount of pepper all over and press in with heel of palm. Place meat in shallow baking dish. Combine ketchup, paprika, and garlic; gradually add soy, then vinegar. Pour over meat and refrigerate overnight or all day. Turn meat over several times while marinating. Remove meat from marinade. Let stand at room temperature for 1 hour. Grill over medium heat until done, 20-25 minutes.
Bigger roasts can be cut in half or roasted wrapped in foil at 300 degrees for 2 hours. Loosen foil and brown.
