To prepare a sweet and spicy soup with black eyed peas and sweet potato recipe, you'll need: Sweet potato: Peel and cut the sweet potatoes into small cubes. Peel the black eyes and chop them in half. Saute the onions and garlic in the olive oil over medium heat until the onion is translucent and the garlic is lightly browned. Add the tomatoes and cook until they're soft, about 5 minutes. Stir in 2 tablespoons of the tomato paste and 1 teaspoon of kosher salt. Bring the mixture to boil, then reduce the heat to medium and simmer the soup for 20 minutes, stirring occasionally. Remove the pot from heat and stir in 1 tablespoon of cornstarch. Season with salt and pepper to taste. Serve with sour cream.