Blend tomatoes, jalapeno peppers, and salt in a food processor until you have a slightly chunky salsa.
Heat oil in a large skillet over high heat. Cook pork in hot oil until crispy and caramel colored, about 10 minutes. Pour the salsa over the pork, reduce heat to low, place a cover on the skillet, and cook until the pork pieces are tender and no longer pink in the center, about 30 minutes. Remove and discard any pieces of bone.
Remove a little salsa for eating with chips before pouring over the pork.