Toast & Soak the Chiles: Remove seeds and stems from the pasilla and ancho chiles. Heat a comal over medium heat and toast the pasilla, ancho, and arbol chiles until fragrant and slightly darkened. Remove from heat and place in a bowl. Cover with boiling water and let steep for 20 minutes until softened. Reserve soaking liquid.
Broil the Tomatillos, Onion & Garlic: Preheat your broiler to high. Arrange tomatillos, onion, and garlic on a baking sheet. Broil, turning halfway through: Tomatillos → ~20 minutes, Onions → ~17 minutes, Garlic → ~10-12 minutes. Use your instincts—cook until deeply charred but not burnt.
Blend the Salsa: In a blender, combine rehydrated chiles, roasted garlic, onion, beer, and mandarin juice. Blend on high until smooth. Add roasted tomatillos and salt, then blend on low until just combined (not overly pureed). Taste and adjust seasoning—chicken bouillon is an optional addition for extra umami.
Finish & Serve: Spoon the salsa into a molcajete or a bowl and top with cotija cheese and raw diced onion. Serve warm or at room temperature with barbacoa, birria, tacos, or grilled meats.
