4 pounds sweet potatoes
2 pounds carrots
5 cups water
2 tablespoons sugar
1 stick unsalted butter
Kosher salt and freshly ground black pepper
1 cup plain yogurt
1 teaspoon freshly grated nutmeg
¼ teaspoon ground cayenne pepper
1. Bake: Scrub potatoes. Cut a slit in each. Set on the center rack of 375-degree oven. Bake until tender when squeezed, about 1 hour.
2. Boil: Peel and trim carrots. Cut into 1-inch lengths. Tumble into a big saucepan. Pour in water, sugar, 2 tablespoons butter, salt and pepper. Set over medium heat. Bring to a boil, cook uncovered until water has evaporated and carrots begin to sizzle in the butter, about 30 minutes.
3. Swirl: Scrape out flesh of sweet potatoes and combine with carrots in food processor. Add remaining butter, the crème fraiche, nutmeg and cayenne. Process very smooth.
Provenance: Adapted from The Silver Palate