How to Make It
Pour water in a medium saucepan to a depth of 1 inch. Bring to a simmer over medium heat; adjust as necessary to maintain a low simmer. Make a small foil bowl; place red beets in foil bowl. Place foil bowl on 1 side of a steamer basket; place golden beets on the other side (to keep the color of the red beets from bleeding onto the golden beets). Place steamer basket over simmering water; cover and steam until beets are very tender, 20 to 30 minutes. Keeping beet colors separate, peel beets under cold running water. (Use paper towels to handle, if desired.)
Combine shallot, vinegar, thyme, salt, Dijon and pepper in a large serving bowl. Slowly whisk in oil. Add cooked beets, watercress and Chioggia beets; toss to coat. Sprinkle with goat cheese and pistachios.