For the mushroom duxelles
Finely chop the mushrooms and heat a large non-stick pan over medium to medium-high heat. Add the butter and swirl to melt to avoid burning. Add the mushrooms and the shallots and season nicely. Cook until the mushrooms release their liquid and continue to cook until the liquid evaporates and the mushrooms appear dried. Then, add the cream, reduce a little and reserve in the fridge.