Fill a pan with cold water and throw in the clove of garlic. Bring to the boil and then add salt and the peas. Cook until tender, drain, and put into a food processor, or blender, and add the creme fraiche, cheese, and dried mint. Puree the peas until knobbly and check the seasoning, adding salt if you need to. Tip the pureed peas into a bowl (or back in the pan is probably a better idea) and cover to keep them warm.