Red Chili - Marinated Chicken Roasted with Potatoes (pollo adorado con papa

Ingredients

• 3 tbs vegetable oil plus a little for the potatoes
• 2 oz dried Ancho chiles stemmed seeded and torn into flat pieces
• 1. oc guajillo peppers
• 3 cloves garlic
• 1 teaspoon Mexican Oregano
• 3/4 tsp pepper
• 1/2 tsp cumin
• 1/4 tsp ground cloves
• 1 tsp sugar
• salt
• 1/3 cup cider vinegar plus 1 tbs
• 3 1/2 lbs whole chicken
• 10 small red skin potatoes scrubbed and halved
• 1 med white onion thinly sliced
• Spring of watercress for garnish