Brown bacon over medium-high heat in Dutch oven until most of the fat released.

Meanwhile, cut onion into quarters; set one quarter aside. Coarsely chop remaining onion.

Add chopped onion, carrots, and garlic pot, season with a big pinch of salt, and sauté, stirring occasionally, until vegetables are softened but haven’t taken on color.

Add chiles along with their liquid, adobo sauce, oregano, and cumin to pot and cook, stirring, until fragrant.

Add beans, 2 tsp. salt, and 2 quarts water. Bring to a boil & then reduce to a simmer.

Meanwhile, thinly slice reserved onion and transfer to a small bowl. Add lime juice and remaining ½ tsp. salt. Let sit, tossing occasionally, until ready to use.

Using a blender, purée soup until smooth. Do this in batches unless using an immersion blender.

Divide soup among bowls. Top with sour cream, corn chips, cilantro, and drained pickled onions. Serve with lime wedges for squeezing over.