Beets with Chicories, Yogurt, and Sherry Mustard Vinaigrette

Preheat oven to 400ºF. Trim beet greens from beets, leaving 1 inch of stems attached; reserve beet greens for another use. Scrub beets thoroughly, leaving tails intact. Place beets on a rimmed baking sheet. Drizzle evenly with olive oil, and sprinkle evenly with 1 tablespoon of the kosher salt; toss to coat. Roast in preheated oven until beet skins are charred and wrinkled and beets are tender when pierced with a paring knife, about 45 minutes, rotating baking sheet from front to back halfway through cook time. Remove from oven. Let cool to room temperature, about 25 minutes.

Whisk together shallot, vinegar, mustard, salt, and pepper in a small bowl. Gradually add oil, whisking constantly. Set aside until ready to use.

Transfer cooled beets to a cutting board. Cut off and discard stem ends. Slice beets crosswise into 1/2-inch-thick slices, leaving the thin, crunchy tails of the beets attached to the last slice. (If the tails are thick and soft, cut off and discard.) Arrange beet slices in a single layer on a large platter, arranging slices with tails around edges of platter so they stick out decoratively. Drizzle beets with finishing-quality olive oil, and, using your fingertips, gently pat oil onto beets to coat and make them glisten. Using your fingertips, crush flaky sea salt over beets.

Place Castelfranco leaves in a large, wide-mouthed bowl. Squeeze lemon juice over leaves; sprinkle evenly with remaining 1/4 teaspoon kosher salt, and toss to coat. Drizzle Sherry Mustard Vinaigrette evenly over leaves, and toss with your hands, massaging each leaf with dressing to coat.

To build the salad, build 4 large "nests" of dressed lettuce on top of beet slices, starting with the larger leaves. Spoon yogurt evenly into lettuce cups, and sprinkle evenly with lemon zest.