Step 1: Prepare the tortilla strips : Preheat your oven to 375°F (190°C). Toss the tortilla strips with oil and a pinch of salt. Spread evenly on a baking sheet and bake for 8–10 minutes, flipping halfway, until golden and crisp. (Alternatively, you can fry them in a skillet with a small amount of oil until crispy.)
Step 2: Sauté the aromatics : Heat olive oil in a large pot over medium heat. Add chopped onion and cook for 4–5 minutes until soft and translucent. Add minced garlic and cook for another 30 seconds until fragrant.
Step 3: Add tomatoes and spices : Stir in the chopped tomatoes and cook until they start breaking down, about 5 minutes. Add chipotle peppers, cumin, chili powder, smoked paprika, salt, and pepper. Stir well to combine and let the mixture cook for another 2–3 minutes to deepen the flavor.
Step 4: Add broth and simmer : Pour in the vegetable broth. Bring the mixture to a boil. Reduce heat to low and let it simmer for 15–20 minutes to allow the flavors to meld together.
Step 5: Blend (optional) : For a smooth soup, use an immersion blender to puree the soup until creamy. For a more rustic texture, leave it slightly chunky.
Step 6: Finish the soup : Stir in lime juice and chopped cilantro. Taste and adjust seasoning with more salt, pepper, or lime as needed.
Step 7: Serve : Ladle the hot soup into bowls. Top with crispy tortilla strips, diced avocado, cheese, and a dollop of sour cream. Garnish with extra cilantro and lime wedges.