Step 1 In a bowl, whisk together the rice vinegar, water, oil, Dijon, shallot, garlic, sugar, salt and pepper to taste until blended.
Step 2 Cook the haricots verts in boiling water about 1 minute, then drain. Rinse them under cold running water and drain thoroughly. Rinse the tomatoes under cold running water in a colander. Remove the stems. Place the beans and tomatoes in a serving bowl.
Step 3Pour the dressing over the vegetables and toss. Toss in the mixed greens.