Slice the mushrooms and season generously with salt. Place them into the dutch oven and cook until all of the water is gone. Finely dice one shallot and add it to the mushrooms. Continue cooking on medium heat for a few more minutes. Make sure not to brown the mushrooms and shallot. 2 to 3 minutes before the mushrooms are done, add one clove of finely diced garlic and a knob of butter. Sprinkle some flour on the mushrooms and cook a bit longer. The flour will help thicken the sauce. Deglaze the pan with ½ cup of white wine. Reduce the wine au sec then add ½ cup of white stock. Place a bouquet garni consisting of thyme, bay leaf, parsley stalks, tarragon, and leek. Put the chickens back in. Cover and cook for 30 to 45 minutes.