2 bunches (6 to 8) beets, with the greens (about 2 pounds beets and 3/4 pound greens)
Salt to taste
3/4 cup milk
1 tablespoon extra virgin olive oil
2 large garlic cloves, minced
1/3 cup chopped chives (1 bunch)
2 ounces Gruyere cheese, grated (1/2 cup)
Freshly ground pepper to taste
1. Roast the beets. Remove from the heat and allow to cool, then cut the ends off, slip off the skins and slice across the equator.
2. Bring a large pot of water to a boil while you stem and wash the greens in two changes of water. Fill a bowl with ice water. When the pot of water comes to a boil, salt generously and blanch the greens for about one minute. (You can also steam the greens until they wilt, one to two minutes). Transfer the greens to the ice water, then drain and squeeze out the water. Chop coarsely.
3. Heat the olive oil over medium heat in a medium skillet, and add the garlic. Cook for about 30 seconds, stirring, until fragrant. Stir in the greens. Stir together for a minute, season the greens with salt and pepper, and remove from the heat.
4. Preheat the oven to 375 degrees. Oil a 2-quart gratin or baking dish with olive oil. Beat together eggs, salt (about 1/2 teaspoon), pepper, milk, chives and the Gruyère. Gently stir in the greens and beets. Scrape into the gratin dish. Bake 35 to 40 minutes until set and lightly browned on the top. Allow to sit for 10 to 15 minutes before serving. Serve hot, warm or room temperature.