3 cups chicken or vegetable stock (fresh, canned, or even bouillon paste)
1 large yellow onion (don’t use Vidalia or other sweet onion)
12 ozs mushrooms, sliced thin
1-2 tbs olive oil
1 cup grated cheese, gruyère, cheddar, swiss, or other firm and flavorful cheese (measure after grating the cheese).
½ cup heavy cream
salt to taste
Melt the butter at medium heat in a medium sized, heavy bottomed sauce pan. When the butter is melted, whisk in the flour and let it bubble for about a minute to cook the flour, making sure that it doesn’t burn.
Add the milk and bring the mixture to the boil, still over a medium flame and stirring constantly to make sure it doesn’t burn. (You can speed this process by preheating the milk in a microwave beforehand.) When the mixture has thickened set it aside.
Mince the onion and slice the mushrooms quite thin. Grate the cheese coarsely and set it aside.
heat a large, heavy bottomed saucepan and add the oil, onions and mushrooms. Sauté the vegetables until the mushrooms have absorbed the oil, then cover and sweat them until the juices come out. At that point, remove the cover and fry them some more until liquid has evaporated and the onions start to brown.
Add the broth, bay leaf, paprika, nutmeg and black pepper. Bring the soup back to the boil then simmer for 5 minutes.
Add the roux, the grated cheese and stir until the cheese has melted into the soup. At this point you can hold the soup until you are ready to serve.
Add the cream just before serving and taste it for salt, adding more if needed.