In a heated saucepan, add butter and saute shallots and garlic until lightly brown, about 3 minutes. Add chestnuts and truffles and season. Add chicken stock and bring to a simmer. Reduce by 1/3 and add cream and truffle oil. Bring back to a simmer and check for seasoning. Transfer to a blender and puree smooth.
Pour the pureed mixture into 4 coffee cups, 2/3 full. Steam like a cappuccino. Garnish on top with minced truffle and serve immediately.