Perfect for a quick evening supper. This time of year we still have a few onions left as well as beets and potatoes from the fall harvest.
1 pound beets, trimmed and scrubbed
1 medium onion, thinly sliced
6 tablespoons extra-virgin olive oil (I use our high-oleic safflower oil from The Oil Barn®)
1 tablespoon thyme leaves, fresh (1 teaspoon dried)
1 pound potatoes, peeled and cut into 1/4 inch slices
1 pound plum tomatoes, cut crossways into 1/4 inch slices
salt and fresh ground pepper to taste
Preheat oven to 400 degrees. Wrap beets tightly in parchment-lined foil. Roast on a baking sheet until tender, about 1 1/2 hours. Let cool, then peel and cut crossways into 1/4 inch slices.
Increase oven temperature to 425 degrees. Toss onion with one tablespoon of oil and half the thyme. Season with salt and pepper and arrange in the bottom of a 3-quart round or oval gratin dish.
Arrange the potato, beet and tomato slices overlapping in rounds. Season with salt and pepper, drizzle with 2 tablespoons of oil and the remaining thyme. Cover tightly with parchment-lined foil.
Bake for 30 minutes, uncover and drizzle with the remaining 3 tablespoons of oil. Bake uncovered until veggies are tender and the tomatoes are caramelized (about 35 minutes more).