1 20-ounce jar guava shells in syrup,* strained, 5 tablespoons syrup reserved, shells pureed
1 tablespoon chopped fresh cilantro
Directions
Blend 1 cup lime juice, garlic, achiote paste, oregano, and cumin in processor until smooth. Season marinade to taste with salt and pepper. Place marinade in medium bowl. Add chicken; stir to coat. Cover and refrigerate chicken overnight.
Preheat oven to 400°F. Place chilies on small baking sheet. Roast until soft, about 20 minutes. Stem and seed chilies. Transfer chilies to processor. Add pureed guava, reserved guava syrup, cilantro, and remaining 1/2 cup lime juice. Process until smooth. Season sauce to taste with salt and pepper. Transfer to medium bowl. (Sauce can be made 1 day ahead. Cover and refrigerate. Bring to room temperature before using.)
Prepare barbecue (medium-high heat). Remove chicken from marinade. Divide chicken among 8 eight-inch metal skewers. Grill until chicken is cooked, turning once, about 7 minutes. Serve, passing guava sauce separately.