Filet Charlemagne Avec Champignons - olive oil

Method

• In a frying pan, heat olive oil then saute onions until softened and then add button mushrooms. Saute for about 6 minutes, until most of the liquid has evaporated. Remove from heat and stir in tomato paste. Set aside. Note that This duxelle [minus the paste] can be made ahead of time and will keep for two days in the refrigerator and you can use it to flavor stuffings, potatoes, casseroles, and soups.
• In the same pan, heat vegetable oil over high heat adding the portabellos and saute until soft.
• Serve the portabello filets with a layer of mushroom filling and hot [1 1/2 cups] demi-glace.
• Demi-Glace [reduction sauce]:.
• In a large saucepan, heat oil adding all the vegetables and saute until the onions are a golden brown (about 6 minutes).
• Add the tomato paste and the garlic. Saute until the tomato paste is well combined with the vegetables.
• Add half the red wine and allow it to reduce by one third of the volume. Add the other half of the wine and allow to reduce by one third.
• Add the bay leaf, water, and thyme. Bring to a simmer, and allow to reduce by half. Strain the sauce.
• Serve hot, or refrigerate until ready to use.
• Demi-glace is done when it coats the back of a spoon. If not thick enough, arrowroot dissolved in a little cold water can be added.
• [This can be used with other recipes or as a stand alone sauce].