How to Make It
Preheat oven to 425°F. Place beets and water in a shallow baking dish. Cover tightly with aluminum foil, and bake in preheated oven until beets are fork tender, 45 to 50 minutes. Uncover and cool slightly, about 15 minutes. Peel and cut into ½-inch wedges; set aside to cool completely, about 30 minutes.
Sprinkle steak with 1 teaspoon of the salt and several grinds black pepper. Heat 1 tablespoon of the oil in a large cast-iron skillet over medium-high. Cook steak until desired degree of doneness, about 4 minutes per side for medium-rare. Transfer to a cutting board; let rest 10 minutes before slicing across the grain.
Combine beets, radicchio, vinegar, honey, thyme, 2 tablespoons of the oil, ½ teaspoon of the salt and ¼ teaspoon of the pepper in a large bowl; toss to coat. Stir together yogurt, and remaining ½ tablespoon oil, ¼ teaspoon salt, and several grinds black pepper. Spread yogurt mixture on a platter or each of 4 plates. Top with sliced steak, beet mixture, and pepitas.