Clean and quarter the mushrooms and finely dice the shallot. Melt the butter in a skillet over a medium heat. Add the shallots and sweat for a minute to soften.
Step 2
Add the mushrooms and cook for 2-3 minutes to soften and brown.
Step 3
Add the stock and heavy cream and stir well to combine, gently heating through.
Step 4
Add the grated cheeses and stir until melted and the sauce has thickened. Serve hot.