- In large pot, heat 1 tbsp oil over medium heat.
- Add onion, celery and green pepper, and cook, stirring often, until vegetables are softened, about 10 minutes.
- Add garlic, cumin and oregano, and cook, stirring often, until fragrant, 2 to 3 minutes.
- Add beans and 6 cups water.
- Bring to a boil, reduce heat, and simmer, partially covered, until beans are tender, about 1¾ hours.
- Add 1½ tsp salt.
- With slotted spoon, transfer 1 cup beans to food processor or blender.
- Add tomatoes and chipotles, and process until smooth.
- Return mixture to pot.
- Stir in sherry, increase heat and bring soup to a boil.
- Reduce heat.
- Simmer about 15 minutes to reduce liquid.
- Meanwhile, in large nonstick skillet, heat remaining 1 tbsp oil over medium heat.
- Add tortilla strips in batches, and toss frequently and gently (for best results, use tongs) to brown evenly, about 3 minutes.
- Adjust heat as necessary.
- Remove to paper towels to blot excess oil.
- Place tortilla strips, avocado and lime cream in separate small bowls.
- Serve soup hot with garnishes along side.
- To make this soup in a pressure cooker, heat 1 tbsp oil in pressure cooker.
- Add onion, celery and green pepper.
- Cook, stirring often, over medium-low heat until vegetables are softened, about 10 minutes.
- Add garlic, cumin and oregano, and cook another few minutes, until fragrant.
- Add beans and 4 cups water, and cover.
- Bring to a boil, lock lid into place, and bring to high pressure.
- Cook over high pressure 15 minutes.
- Turn off heat, and let beans return to pressure naturally.
- Remove lid, and add 1½ tsp salt.
- Proceed with step 7, above.