Ingredients

• 4 guajillo chiles, stemmed and seeded
• 2 ancho chiles, stemmed and seeded
• 4 cloves garlic, chopped
• 2 chipotle chiles in adobo
• ¹⁄₂ small white onion, chopped
• 4 tbsp. extra-virgin olive oil
• 2 tbsp. light brown sugar
• 2 tbsp. red wine vinegar
• 1 tsp. salt
• ³⁄₄ tsp. pepper
• 1 (2-lb.) piece of beef tenderloin
• 1 ¹⁄₂ tsp. coarse sea salt
• 3 tbsp. very finely ground coffee
• 1 tbsp. cocoa powder
• ¹⁄₈ tsp. ground cinnamon

Instructions

1. Toast guajillo chiles and ancho chiles in a skillet over medium heat for 4–5 minutes; soak in warm water until soft, about 30 minutes. Purée chiles, 1 cup soaking liquid, garlic, chipotle chiles, and onions in a blender until smooth.
2. Heat 2 tbsp. of the olive oil in a small saucepan over medium-high heat. Add purée, reduce heat, and simmer until thickened, about 30 minutes. Add brown sugar, vinegar, salt, and 1⁄4 tsp. of the pepper; simmer until thickened, 12–14 minutes more; let sauce cool.
3. Preheat oven to 400°. Tie tenderloin with butcher's twine at 1⁄2" intervals. Rub with remaining 2 tbsp. olive oil, sea salt, and remaining 1⁄2 tsp. pepper; brush all over with 2 tbsp. sauce (save remainder for another use).
4. Combine coffee, cocoa powder, and cinnamon; roll beef in mixture to coat. Place beef on a rack in a roasting pan; let sit for 30 minutes. Roast for 10 minutes; reduce temperature to 225° and continue roasting until a thermometer inserted in the thickest part reads 125°, about 50 minutes. Let rest for 15 minutes. Remove twine and slice.