In a large pot over medium heat, heat oil. Add the onion, garlic, jalapeño, salt, and pepper, and cook, stirring occasionally until the onions are soft and translucent, about 5 minutes. Add the chili powder and stir for a minute to toast the spice.
Add the chipotles in adobo (sauce or chopped) and crushed tomatoes and stir while cooking for about 3 minutes until they come to a simmer.
Once simmering, add the vegetable broth, corn, and 2 cups of water. Bring to a simmer and reduce heat to low and continue cooking for 20 minutes.
Serve:
To serve, squeeze 1 to 2 lime wedges over the soup, place a handful of tortilla strips over the soup, submerge with a spoon to soften up, top with chopped cilantro and fresh avocado pieces.