To make the soup, coat the bottom of a medium pot with oil and place it over medium heat. When the oil is hot, add the onion and poblano pepper. Sauté until soft and the onion is translucent, about 5 minutes. Add the garlic and continue to sauté until very fragrant, about 1 minute more.

Add the beer (if using) broth, tomatoes, beans, cumin, and lime juice. Raise the heat and bring everything to a simmer. Lower heat and allow to cook, uncovered, for 30 to 60 minutes. (Cooking for longer will cause the beans to start to fall apart and you'll end up with a nice thick base, whereas a shorter cook time will give you a soupier base.)

While the soup cooks, prepare the tortilla strips. Preheat the oven to 400° and line a baking sheet with parchment paper. Lightly brush the strips with oil and arrange them on the baking sheet in an even layer. Bake until crisp and browned around the edges, about 10 minutes.

Remove the soup from heat and season with salt and pepper to taste. Ladle into bowls and top with tortilla strips, avocado slices, cilantro, and hot sauce. Serve.