Chipotle Chicken Tacos with Potatoes and Guacamole

Ingredients

• 2  ancho chili pepper dried stemmed seeded
• 1 tablespoon chipotles in adobo canned chopped
• 12  corn tortillas fresh
• 3  garlic clove peeled
• 0.5 teaspoon ground cumin 
• 2 tablespoons olive oil 
• 1 slice onion white (1/2"-thick)
• 1 sprigs pecorino store-bought crumbled sliced (or use )
• 1 pound chicken thighs boneless skinless chilled cut into roughly 1 1/2" pieces
• 0.5 pound tomatoes ( 2" diameter)
• 2 tablespoons water cold
• 0.5 pound yukon gold potatoes peeled cut into 1/2" cubes

Equipment

• food processor
• frying pan
• baking sheet
• oven
• pot
• blender
• aluminum foil
• broiler
• meat grinder

Directions

1. Preheat broiler.
2. Soak ancho chiles in boiling water (1 cup), 5 minutes.
3. While chiles soak, broil tomatoes, onion slice, and garlic on a foil-lined rimmed baking sheet 3"-4" from heat, turning once, until lightly charred, 5-7 minutes.
4. Drain chiles, discarding soaking liquid, and add to blender with tomatoes, onion, garlic, chipotles with sauce, cumin, 1/2 teaspoon salt, and cold water (2 tablespoons). Purée until smooth.
5. Preheat oven to 350°F. Wrap 2 stacks of tortillas in foil; warm in oven while finishing filling.
6. Cook potatoes in a 3- to 4-quart pot of well-salted boiling water until just tender but not falling apart, 5-7 minutes.
7. Drain.
8. Coarsely grind chicken in a meat grinder or food processor (or use pre-ground meat).
9. Heat oil in a 12" heavy skillet over medium-high heat until it shimmers.
10. Add chile purée (it will splatter) and cook, stirring, 4 minutes (sauce will thicken).
11. Add ground chicken and cook, stirring and breaking up clumps, 1 minute. Cover skillet and reduce heat; simmer, stirring occasionally, until chicken is cooked through, about 4 minutes.
12. Gently stir in potatoes and reheat.
13. Serve chicken and potatoes with warm tortillas and accompaniments.