Melt a piece of butter in a saucepan and sauté the finely chopped shallots. Add the rice and sauté until translucent. Deglaze alternately with white wine and broth and let reduce.
Clean the king oyster mushrooms, roughly chop them and fold them into the almost finished risotto. Just before the end of the cooking time, fold in the remaining butter and parmesan. Season to taste with thyme, salt and pepper.