Chicken Fajitas with Red Grapefruit Salsa

To prepare salsa: Working over a medium nonreactive bowl, supreme grapefruit (see Tips). Squeeze the membranes to extract any extra juice. Drain all the juice into a separate bowl and set aside. Add tomato, bell pepper, jalapeño, onion, lime juice and 1/2 teaspoon salt to the fruit; mix well. Refrigerate for at least 30 minutes and up to 2 hours. Stir in cilantro just before serving.

To prepare fajitas: Cut chicken in half horizontally, holding the knife parallel to the cutting board. Place the chicken between 2 large pieces of plastic wrap. Pound with the smooth side of a meat mallet or a heavy saucepan to an even 1/4-inch thickness.

Combine oil, garlic, oregano and the reserved grapefruit juice in a large shallow nonreactive dish. Add the chicken to the marinade; turn to coat well. Cover and refrigerate for at least 1 hour and up to 2 hours.

Preheat grill to medium-high or heat a grill pan over medium-high heat. Remove the chicken from the marinade and let stand at room temperature while the grill heats. (Discard marinade.)

Season the chicken with salt and pepper. Oil the grill rack (or pan). Grill the chicken, turning once, until just cooked through, 5 to 7 minutes total.

Transfer the chicken to a clean cutting board. Slice crosswise into 1/2-inch-thick strips. Serve with tortillas and the grapefruit salsa, garnished with radishes and/or jicama, if desired.