1 bunch cilantro, stems removed and coarsely chopped
1 15-ounce can white hominy, drained and rinsed
Lime wedges, for serving
In a stockpot, combine 2 quarts of water, a pinch of salt, bay leaf and fish bones. Cover, bring to a simmer and let cook for 20 minutes. Turn off stove, uncover and let cool.
Strain broth through a fine-meshed sieve into a medium bowl. Pick cooked fish off bones; reserve.
Rinse and dry stockpot. Place over medium heat, add 2 tablespoons oil and swirl to coat. Add onion; sauté until translucent, about 5 minutes. Add garlic, cumin, coriander and chili powder; cook, stirring often, until fragrant, about 2 minutes.
Add tomatillos and Serrano chili; cook, stirring, until tender, about 2 minutes.
Stir in reserved fish broth, cooked fish, cilantro and hominy. Bring to a boil, then reduce heat to low. Cover and simmer, stirring occasionally, for 15 minutes. Ladle into bowls and serve with lime wedges.