1. Bring a large pot of water to a boil. Whisk together the white wine vinegar and the next 4 ingredients (through tarragon) in a small bowl; set aside.
2. Add the peas and the edamame to the pot; cook 3–4 minutes or until just cooked through. Stir in the sugar snap peas, and continue to cook 3 minutes more or until tender-crisp. Drain and rinse under cold running water until no longer warm. Drain well, and pat dry with a towel.
3. Line a serving bowl with the mixed salad greens. Add the peas and radishes to a serving bowl, and drizzle with the dressing right before serving.