Yum, great mash-up. Coconut, curry and sweet potatoes are balanced so well here.
2 ½ pounds sweet potato (3 or 4 large), scrubbed and cut into 1 ½ inch chunks
4 tablespoons (1/4 cup) unsalted margarine
1 tablespoon mild curry powder
¼ teaspoon ground cinnamon
Pinch of cayenne pepper
¾ cup coconut milk
1 teaspoon freshly squeezed lemon juice, more as needed
6 tablespoons toasted coconut flakes, sweetened or unsweetened (see note)
Fit a steamer basket into a large pot, add water just to the bottom of the basket, and arrange the sweet potatoes in a snug layer in the basket. Bring the water t a boil over medium-high heat, cover the pot, and lower the heat to maintain a vigorous simmer. Cook until the potatoes are completely tender when pierced with a skewer, 15 to 20 minutes. (Keep an eye on the water level during cooking, and add ore if it threatens to boil off.) Remove from the heat, carefully remove the potatoes from the basket, and set aside.
Pour the water out of the pot and return to medium heat. Add the margarine, curry, cinnamon, and cayenne and cook, stirring constantly, until the margarine is melted and the spices are fragrant, about 2 minutes. Add the coconut milk and 1 ½ teaspoons salt, bring to a simmer, and cook for an additional minute to thicken slightly. Remove from the heat and stir in the lemon juice.
Carefully peel off and discard the potato skins. Add the potatoes to the pot and mash until smooth and all ingredients are blended. (At this point you can adjust the consistency of the potatoes by adding up to ½ cup of water.) Taste and add more salt or lemon juice as needed. If necessary, rewarm over low heat, stirring constantly.
To serve, transfer to a serving dish and top with the coconut.
You can make these potatoes up to a day ahead. Reheat in a covered ovenproof dish in a 350 degree oven until heated thorough, about 40 minutes. Garnish just before serving.
Note: to toast coconut, spread it in an even layer on a rimmed baking sheet and bake in a 350 degree oven, stirring occasionally, until golden.