For this colourful vegetarian dish start by slowly cooking your polenta. Melt the butter stirring in the polenta and then adding the milk a little at a time. Keep on a low heat and stir for 5-10 minutes until smooth and silky. Then add some grated parmesan to finish.
Heat another pan with melted butter until it starts to brown and then add in your sliced mushrooms, thyme, garlic and shallots. Once they brown after 3-4 minutes on a high heat pour in a glass of Vermouth and reduce until the alcohol burns off, or alternatively flambé.
Then stir in the double cream until smooth and incorporated as a delicately aromatic sauce. Serve the mushroom ragu on top of your polenta and garnish with extra grated parmesan.