Bring a large pot of salted water to a boil. Rinse and sort the potatoes by color.

While you’re bringing it to temperature, cut the potatoes into bite sized pieces. I like them quite small for this salad, since the beans and mushrooms are small. I sort the purple potatoes and boil them separately because they cook faster, and they can stain the water.

Trim the ends of the green beans and cut them into 1 inch lengths. (If you’re also making the Asparagus and Dill Roast Beef Rolls prep the asparagus now). When the water is boiling, blanch the beans for 60-90 seconds and then remove to a colander in the sink using a slotted spoon.

Run cold water over them to stop the cooking. Repeat with the asparagus. Set aside.

Add the red and white potatoes. Cook until fork tender (10-15 minutes). Again, remove to a colander to cool with a slotted spoon.

Finally, cook the purple potatoes (check after 7 minutes).

When the potatoes have cooled enough so that they’re easy to handle, put them in a large salad bowl.

Add the beans, marinated mushrooms, capers, and tarragon. Toss well. Add ¼ cup olive oil and red wine vinegar. Toss well. Salt and pepper to taste, but do taste often. The capers and the mushrooms are quite salty themselves.

If you’re making the Asparagus and Dill Roast Beef Rolls assemble them. Once you’re finished, cut any remaining asparagus into ¼ inch rounds and add to the salad.