Heat the Avocado oil or two tablespoons of the olive oil in a saucepan and add chopped onion. Saute for 5 minutes and add garlic, ginger and 2 of the peppers. Saute for another 5 minutes. Add the stock, simmer for 10 minutes and remove from heat. While the stock and vegetables are simmering, cut the Avocados in half and seed and peel them. Chop the Avocados, toss them with the juice of 1 lime and place about half the Avocado in a blender container. Add hot stock and vegetables until container is about 3/4 full and process until the mixture is smooth and liquid. Chill the soup thoroughly, preferably for several hours. To make the cilantro cream, stir the sour cream and half-and-half together, add the chopped cilantro, the remaining chili pepper, the ground coriander and salt to taste. Chill until you are ready to use it. Cut the radishes in small julienne and toss with the walnut oil or the remaining olive oil, the juice of 1/2 lime and salt to taste. Chill until you are ready to use them. Taste the chilled soup and add salt and more lime juice to taste. Ladle it into chilled soup bowls. Top each serving with a tablespoon of cilantro cream and a tablespoon of julienned radishes. Variation This soup is also delicious when served hot and is an ideal opening to a hearty Mexican meal.