Combine guava, vinegar, garlic, onion, ancho and honey in a small saucepan and reduce to 1/2 cup. Place 2 skewers through each thigh and season with salt and pepper. Brush with glaze and grill 4 minutes per side. Brush with glaze several times while on grill. Cut each thigh in half and serve.
Recipe courtesy of Food Network Kitchens