This novel take on succotash brings together fresh beans, corn, sugar snap peas, and tomatoes with an avocado dressing.
Prepare an ice-water bath. Cook cranberry beans in a large pot of salted boiling water until just tender, 15 to 20 minutes. Transfer to ice-water bath. Drain. Repeat with haricots verts, wax beans, and sugar snap peas, cooking together for 2 minutes. Repeat with scapes if using, cooking for 1 minute. Repeat with corn, cooking for 2 minutes. Cut kernels off cobs.
Whisk oil, vinegar, and tarragon in a small bowl. Season with salt and pepper, and mash in 3 avocado pieces. Place cooked vegetables, remaining avocado, and the tomatoes in a large bowl, and toss with dressing. Serve immediately.