In a 6- to 8-quart Dutch oven combine sweet potatoes, turnips, and enough water to cover. Bring to boiling; reduce heat. Simmer, covered, for 12 to 15 minutes or until tender. Drain well in a very large colander. Return vegetables to the Dutch oven and add the 3 tablespoons butter and 1 teaspoon salt. Mash vegetables with a potato masher until nearly smooth.

For the relish, in a medium skillet melt the 2 tablespoons butter. Add apples, dates, and brown sugar. Cook and stir until sugar is dissolved and apples are just tender. Stir in lemon juice.

To serve, mound hot vegetables in a serving bowl and garnish center with the relish. Makes 10 to 12 side-dish servings.

Prepare vegetables as directed. Place in a 2- to 2-1/2-quart microwave-safe dish; cool slightly, then cover, and refrigerate. To reheat, microwave, covered, on 70 percent power (medium-high) for 20 to 25 minutes or until heated through, stirring twice. Make relish before serving.