Boil the potatoes until just tender, about 10 minutes. While the potatoes cook, place the vinegar, mustard, honey, tarragon, salt and pepper in a large bowl. When the potatoes are cooked, drain well and add them to the bowl. Add the frozen peas, snap peas and snow peas. Toss to combine. This salad can be served warm, or, cooled to room temperature, refrigerated and served cold.
Note: To blanch the snow and snap peas, plunge into boiling water for 30 seconds. Drain well, cool in ice-cold water, and then drain well again.