In a large saucepot, add butter, shallots, garlic, thyme, red pepper and curry powder; sauté until shallots are translucent, about 2 to 3 minutes. Add yams; mix well. Add the Chablis, sherry, and lemon juice; cook on high heat for 4 to 5 minutes. Add chicken stock; bring to a boil, lower heat and simmer until yams are soft. Add heavy cream and simmer for 5 more minutes. Use an immersion blender to puree the soup to a smooth and velvety consistency. Or, puree the soup in batches using a blender or food processor. Season with salt and pepper; chill soup. Marinate prawns in satay sauce for 30 minutes. Skewer prawns onto lemongrass stalks. In a medium skillet, sauté prawns until pink. To serve, pour chilled soup into serving bowls and garnish with skewered prawns. Makes 10 servings.
