Sweet Potato and Parsnip Puree

Ingredients:

• 6 tablespoons unsalted butter
• 0.9 kg sweet potato, peeled and cut into large pieces
• 450g parsnips, peeled and cut into large chunks, discarding tough cores
• 4 sprigs of thyme[u][/u]
• 1/4 tsp freshly grated nutmeg, plus extra for sprinkling
• 0.5 cups low-fat cream
• 1 teaspoon sherry vinegar

Preparation:

1. In a large saucepan or Dutch oven, melt 3 tablespoons of butter over medium heat; cook, stirring occasionally, until browned, about 5 minutes. Add the sweet potato, parsnips, thyme sprigs, nutmeg, 1 tablespoon of salt, and a few freshly ground black pepper. Cook, stirring, until the vegetables are well coated with butter.
2. Add 1/2 cup water and cream to the pan, cover, and bring to a boil. Reduce heat to medium-low and simmer, stirring occasionally and adding another 1/4 cup water at a time if the pan seems dry, until the vegetables are very tender, 30-35 minutes (there should be very little liquid remaining).
3. Discard the thyme sprigs and transfer the vegetables and any remaining liquid to a food processor. Add the remaining 3 tablespoons of butter and process until smooth. Add the vinegar and mix well, season with salt and pepper to taste. Transfer the puree to a serving platter. Sprinkle with nutmeg to taste.