Cook the pork shoulder in 7 cups of salted water with 2 jalapeños for about an hour.
Make the sofrito by cooking the white onion, garlic, cilantro stems, tomatoes, and jalapeños in a skillet for about 15 minutes until sizzling.
Add the cooked beans and shredded pork to the sofrito and cook for about an hour to an hour and a half.
Make a quick salsa with the thinly sliced red onion.
Serve the beans with the salsa and fresh cilantro leaves, along with corn tortillas and a large bottle of beer.
