Finely chop the garlic and onion.
Heat the oil, then sweat the onion for 5 minutes.
Meanwhile slice the mushrooms.
When the onion is soft, add the garlic, thyme leaves and mushrooms. Stir for a minute, then put a lid on, turn down the heat and sauté for 8-10 minutes, under cover.
Crumble the cheese over the mushroom (rind removed, if preferred) and stir until you get a thick creamy sauce.
Season with salt and pepper (you can add a pinch cayenne or nutmeg too).
Garnish with fresh herbs (such as parsley, dill, chives or thyme - depending on your meal).
Serve warm.