Step 1

Cook bacon in Instant Pot on Sauté setting, stirring occasionally, until browned and most of the fat is released, 6–8 minutes. (If using a stovetop pressure cooker, cook bacon over medium-high heat.)

Step 2

Meanwhile, cut onion into quarters; set one quarter aside. Coarsely chop remaining onion. Add chopped onion, carrots, and garlic to Instant Pot, season with a big pinch of salt, and cook on Sauté, stirring occasionally, until vegetables are softened but haven’t taken on color, 6–8 minutes.

Step 3

Add chiles along with their liquid, adobo sauce, oregano, and cumin to Instant Pot and cook, stirring, until fragrant, about 1 minute. Add beans, 2 tsp. salt, and 2 quarts water. Lock lid and cook soup at high pressure 20 minutes. Release pressure manually. Taste soup and season with more salt if needed.

Step 4

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.

Step 5

Using an immersion blender, purée soup in pot until smooth (or, working in batches, purée with a regular blender).

Step 6

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