Sopa de Mariscos (Seafood Soup)

Heat olive oil in a stockpot over medium heat. Add onion and cook until translucent, 5 to 7 minutes. Add garlic and cook until fragrant, about 1 minute.

Add carrots, corn, and celery and cook until softened, about 5 minutes. Add chicken stock, tomatoes, ancho chili, chili powder, and cumin and bring to a boil. Reduce heat, cover, and simmer for 45 minutes.

Meanwhile, place clams and mussels in a bowl of cold water to filter out sand.

Drain clams and mussels; add to the soup. Stir in cod and shrimp. Cover and boil until cod is white and flaky, mussels and clams are open, and shrimp is pink, 5 to 10 minutes. Serve immediately, topped with cilantro and avocado.