In a nonstick saucepan, roast the jalapenos over high heat until the skins char. Turn the heat off, cover the pan, and set aside for 5 minutes.
Peel the cooled jalapenos and remove the stems. Slice lengthwise and, over a small bowl, scrape out the seeds and discard while allowing the juices to collect in the bowl.
Add the cilantro, shallots, lemon juice, and salt and pepper to the bowl and whisk to combine. Whisk in the olive oil.
The vinaigrette will keep, tightly covered, in the refrigerator for 2 days.