Beets with Stout and Sauteed Beet Greens

In a kettle cover the beets with 2 inches cold water, bring to a boil, and simmer the beets, covered, for 20 to 35 minutes (depending on their size), or until they are tender. Drain the beets and under the cold running water slip off and discard their skins and stems. In a skillet bring to a boil the stout and the vinegar and whisk in 2 tablespoons of the butter. Stir in the beets, quartered, add the salt and pepper to taste, and keep the beets warm, covered. In a large skillet heat the remaining 2 tablespoons butter over moderately high heat until the foam subsides, in it sauté the reserved beet greens, stirring, for 5 minutes, or until they are tender, and stir in the salt and pepper to taste. Arrange the greens around the edge of a platter and mound the beets in the center.