Cut each rib lengthwise to create 2 or 3 cutlets about ⅜ inch wide. Place cutlets cut side down. Combine lime juice, oil, garlic, annatto powder, sugar, ¾ teaspoon salt, ½ teaspoon pepper, and cori­ander in 1-gallon zipper-lock bag. Add cutlets to bag and toss to coat. Press out as much air as possible, seal bag, and refrigerate for at least 30 minutes and up to 2 hours, flipping the bag occasionally

Just before grilling, remove cutlets from bag and pat dry with paper towels; discard marinade. If using charcoal, use kitchen shears to remove and discard bottom of disposable pan; reserve pan collar.

For a charcoal grill: Open bottom vent completely. Light large chimney starter filled with charcoal briquettes (6 quarts). When top coals are partially covered with ash, place pan collar in center of grill, oriented over bottom vent, and pour coals into even layer in collar. Set cooking grate in place, cover and open lid vent completely. Heal grill until hot, about 5 minutes.

For a gas grill: Turn all burners to high, cover; and heat grill until hot, about 15 minutes. Leave all burners on high.

Clean and oil cooking grate. Place cutlets on grill (over coals if using charcoal). Cook, uncovered, until lightly browned on first side, about 2 minutes. Flip cutlets and

continue to cook until just cooked through, about 30 seconds. transfer cutlets to serving platter; top with avocado, tomato, radishes, and cilantro; and serve immediately.