Enchiladas Divorciadas

Ingredients

• ["1 Tbsp. vegetable oil", "1/2 white onion, coarsely chopped", "4 garlic cloves, crushed", "3 small serrano chiles, halved lengthwise, seeds removed if desired", "12 oz. tomatillos (6-7), husks removed, rinsed, halved", "1 cup cilantro leaves with tender stems", "Kosher salt", "1 Tbsp. vegetable oil", "1/4 white onion, coarsely chopped", "1 garlic clove, crushed", "3 guajillo chiles, seeds removed", "2 dried chiles de arbol (optional; omit for a milder sauce)", "3 plum tomatoes, quartered", "Kosher salt", "1 (3 1/2-4-lb.) chicken", "6 bay leaves", "1 tsp. allspice berries", "Kosher salt", "1/2 cup creme fraiche", "1/3 cup crumbled queso fresco", "1/2 cup vegetable oil", "12 (6\") corn tortillas""