Preheat oven to 350 degrees. Brush tortillas in olive oil and sprinkle some lime salt on to each. Cut each tortilla in half, then cut halves into 1/4-inch strips. Arrange strips in a single layer on a baking sheet. Bake for six minutes or until lightly browned. Combine onion and next nine ingredients (up to bay leaf) in a stockpot. Simmer for 30 minutes. Remove chicken from broth, cool slightly. Remove chicken from bones and cut meat into bite-sized pieces. Discard bones. Strain stock through a sieve into a bowl and discard solids. Return stock to cooker, stir in ground chiles, oregano, cumin and chicken. Let stand 5 minutes. Divide soup evenly among eight bowls. Top each serving with two tablespoons avocado, one tablespoon sour cream, tortilla strips and a pinch of cilantro.