Pollo en Chicha

Name: Pollo en Chicha
Ingredients: 6 skin-on, bone-in chicken thighs; Kosher salt, freshly ground pepper; 2 Tbsp. vegetable oil; 1 large onion, cut into 1 pieces; 4 medium carrots (about 10 oz.), peeled, halved lengthwise; 10 garlic cloves, halved; 10 oz. fingerling potatoes, scrubbed, halved lengthwise; 2 Tbsp. Relajo; ¼ tsp. crushed red pepper flakes; ¾ cup apple cider vinegar; 4 oz. prunes (about 1 cup), halved, pitted; 1 cup pineapple juice; 1 Tbsp. dark brown sugar; 2 cups low-sodium chicken broth; 1 Tbsp. oregano leaves; Sliced pickled chiles and toasted sesame seeds (for serving)