- Simmer chicken thighs in the water in a large stockpot with lid for at least an hour.
- Sauté the onions and garlic in oil until clear, about 3 minutes and add to chicken stock.
- Purée the plum tomatoes and chipotle peppers in Adobo sauce. The chipotle peppers add a good amount of heat so adjust as necessary. Add to chicken stock, cover and simmer for 30 minutes. Season with salt and pepper to taste.
- Cut avocado in half and remove pit and peel. Cut the avocado and lime into small cubes. Place in small bowl for garnish.
- Assemble this soup by putting a few avocado chunks, chopped cilantro and corn chips in each bowl.
- Ladle soup over and top with cheese. Serve with little wedges of lime.
Adobo sauce is made of smoked red jalapeño peppers in spices, vinegar, tomato sauce and ancho chilis. A chipotle pepper (pronounced "chee-POHT-lay")is a red Jalapeño chili, ripened, dried, and smoked through a special process. Derived from the Aztec word meaning smoke, jalapeños are placed over huge pits and smoke is blown through tunnels running underground. They give a unique warm heat and smoky flavor. Chipotles are packed in a red adobo sauce made from lightly seasoned tomato broth in small cans (7 oz/200 g).