- 3 carrots, coarsely chopped
- 3 celery ribs, coarsely chopped
- 2 onions, coarsely chopped
- 1 whole chicken (about 3 1/2 pounds)
- 1 head garlic, halved crosswise
- 3 1/2 quart cold water
- 25 cilantro stems
- 2 Turkish bay leaves or 1 California
- 3 whole allspice
- 1 whole clove
- 1/2 teaspoon cumin seeds
- 1/4 teaspoon black peppercorns
- 1 medium white onion, chopped
- 2 garlic cloves
- 1 1/2 to 2 tablespoons chipotles in adobo, finely chopped, plus 1 tablespoon adobo sauce
- 1 cup medium-or short-grain brown rice
- 1 1/2 pounds sweet potatoes (about 2), peeled and cut into 1/2-inch pieces
- 20 (7-to 8-inch) corn tortillas
- 6 tablespoons vegetable oil
- 1 (15- to 19-ounces) can black beans, rinsed
- 2 (7-to 8-ounces) firm-ripe avocados
- 2 limes, cut into wedges
- 1/2 cup finely chopped cilantro
- Bring all stock ingredients to a boil with 2 teaspoons salt and 1/2 teaspoon pepper in an 8-to 10-quart heavy pot, then skim foam.
- Reduce heat and gently simmer, uncovered, skimming foam occasionally, 2 3/4 hours.
- Transfer chicken to a cutting board, then pour stock through a fine-mesh sieve into a large bowl and discard solids. Reserve
- 1 cup stock and return remainder to cleaned pot.
- Toast spices in a dry small skillet (not nonstick) over medium-low heat, shaking skillet occasionally, until fragrant and a shade darker, about 2 minutes.
- Transfer spices to a blender along with onion, garlic, chipotles with adobo sauce, 2 1/2 teaspoons salt, and reserved stock.
- Blend until mixture is smooth and spices are ground, about 2 minutes (use caution when blending hot liquids).
- Add purée to stock in pot along with rice and sweet potatoes and bring to a simmer over medium heat. Simmer, covered, until sweet potatoes and rice are tender, about 45 minutes.
- While soup simmers, discard skin and bones from chicken and cut or shred meat into bite-size pieces.
- Meanwhile, preheat oven to 375°F with racks in upper and lower thirds. Stack tortillas and cut into 1/4-inch-thick strips, then toss with oil. Spread strips in 1 layer on 2 large baking sheets and season with salt.
- Bake, stirring frequently and switching position of sheets halfway through baking, until deep golden and crisp, 20 to 25 minutes.
- When rice and sweet potatoes are tender, add chicken and beans to soup and simmer, uncovered, until just heated through, about 5 minutes.
- Meanwhile, quarter avocados lengthwise and cut into 1/2-inch cubes.
- Season soup with salt and pepper, then serve with lime wedges, chopped cilantro, avocados, and tortilla strips.