Put 2 pounds beets in a baking dish lined with a large sheet of aluminum foil. Sprinkle with 1 tablespoon olive oil, 3 tablespoons water and 1 teaspoon kosher salt. Bring the foil edges together; fold to seal. Roast at 325 degrees F until tender, 45 minutes for small beets and up to 2 hours, 30 minutes for large ones. Let cool. Peel the beets; cut into cubes. Whisk the juice of 1 lemon, 1 1/2 teaspoons sugar, 1/2 teaspoon salt and 1/4 teaspoon pepper in a bowl; whisk in 3 tablespoons olive oil. Toss with the beets.
TIP: Roasting beets intensifies their sweet, earthy flavor. All they need is a simple vinaigrette.