Mashed Sweet Potatoes with African Flavors Toast ½ teaspoon ground coriander and 1/8 teaspoon cayenne in medium saucepan over medium heat until fragrant, about 30 seconds. Follow recipe for Mashed Sweet Potatoes, cooking butter, cream, salt, sugar, and sweet potatoes in saucepan with toasted spices. Stir in 1 tablespoon chunky peanut butter and 1 tablespoon minced fresh cilantro along with black pepper.