3 (1 pound) calves' hearts, trimmed, or
    1 (2 1/2 pound) boneless beef sirloin steak, 1 inch thick
3 large cloves garlic, minced
1 small red jalapeņo pepper, seeded and minced
2 teaspoons ground cumin
1 1/2 teaspoons salt
2 teaspoons water
15 whole black peppercorns
1 cup red wine vinegar
1/3 cup water
1 tablespoon annatto seed
1/4 cup dried red chile peppers, seeded
1 tablespoon vegetable oil
1 teaspoon salt

Remove nerves and membranes from calves' hearts; cut hearts into 1-inch cubes. Place in large glass bowl. Mash garlic, jalapeņo pepper, cumin, salt, the 2 teaspoons water and peppercorns to a smooth, thick paste, using the flat side of a wooden mallet on cutting surface. Toss garlic mixture with hearts until thoroughly coated. Cover and let stand 10 minutes. Stir in vinegar and the 1/3 cup water. Cover and refrigerate, stirring occasionally, for 24 hours.

Cover annatto seed with boiling water. Let stand at least 12 hours.

Remove heart pieces, one at a time, from garlic mixture, using tongs and shaking off garlic and jalapeņo pieces. Reserve garlic mixture.

Pour 1/2 cup boiling water over chile peppers. Let stand 30 minutes; drain. Drain annatto seed. Place chile peppers, annatto seed, oil, salt and 3/4 cup reserved garlic mixture in blender container. Cover and blend on high speed, stopping blender to scrape sides occasionally, until smooth and well blended, about 3 minutes.

Thread heart cubes on six (11-inch) skewers. Brush with annatto mixture. Set oven to broil or 550 degrees F. Broil with tops about 4 inches from heat for 5 minutes. Turn; brush with sauce. Broil until medium rare, 5 to 6 minutes longer. Heat remaining annatto mixture to boiling; serve with kabobs.

Makes 10 to 12 servings.