Preheat the oven to 350 degrees F.

In a 3-quart or larger pot, heat the oil over medium. Add the onion and cook, stirring occasionally until soft, about 5 minutes. Add the garlic, chili powder, and oregano and cook, stirring often until fragrant, about 3 minutes.

Add the tomatoes and the stock, raise the heat to medium-high, and bring to a boil then lower the heat to medium-low and simmer for 15 minutes.

While the soup is simmering, brush each tortilla with the oil, then stack on a cutting board. Cut the tortilla stack in half, then into 1/2-inch wide strips.

Arrange the strips on a sheet pan in a single layer (you may need to use more than one pan, or bake in rounds.) Season the strips with a few pinches of salt and bake until golden and crispy, about 10 minutes.

Add the turkey meat to the soup pot and season with salt and pepper. Simmer for another 5 minutes to heat the turkey meat.

To serve, top the soup with a handful of tortilla strips and cilantro, plus optional avocado, sour cream and cheese.