To save time, prep the garnishes (avocado, shredded cheese, cilantro, lime wedges) while the soup is cooking in step 3.
1 The first step is to fry strips of corn tortillas. Somewhat dry corn tortillas work best for this, so you can either leave the tortillas out overnight on a rack, or put them in a 200°F oven for 10 minutes. (If your tortillas are too dry, you can soften them by putting them in the microwave for 30 seconds.) Slice them into 1/4-inch wide strips, and then cut the longer strips in half.
Heat oil in a 4 to 5 quart, thick-bottomed pot on medium high heat. When the oil is shimmering hot, working in batches (a third at a time) add the tortilla strips. Fry them until lightly browned at the edges, a minute or so. Use tongs to remove them to a paper towel-lined plate.
2 Add the chopped onions to the pot with the remaining oil. Cook on medium high heat until softened, about 3 to 4 minutes.
Add the garlic, cumin, and minced chipotle chili in adobo and cook for 2 minutes more.
3 Add the crushed tomatoes, turkey (or chicken) stock, and salt. Increase the heat to high, bring mixture to a simmer, lower the heat, and cook at a gentle simmer for 15 minutes.
4 Add the shredded turkey and cook until just heated through, a minute or two.
5 To serve, divide half of the fried tortilla strips into individual serving bowls. Top with the soup. Sprinkle with chopped avocado, shredded cheese, the remaining tortilla strips, and cilantro. Serve with lime wedges.