In a saucepan, cover potatoes with water, add salt and boil potatoes for about 13-17 minutes, or until tender. Do not cook through or potatoes will fall apart.
While potatoes cook, coarsely chop jalapeños and pulse in a food processor with lime juice, cilantro, shallots, garlic, oil, and remaining 2 tablespoons vinegar until finely chopped.
Drain potatoes and rinse under cold water until slightly cooled. Cut into bite size pieces while still warm and gently toss with 1 tablespoon vinegar. Cool potatoes to room temperature.
When potatoes are cool, toss with pepper mixture and serve.