Preparation

• 在中火的大煎锅中，将1汤匙结合在一起。油和1汤匙。黄油。黄油融化后，加入洋葱，煮熟，偶尔搅拌，直到褐色和焦糖化，根据需要调节热量，35至45分钟。大约在烹饪时间的一半，用1/2茶匙调味。盐和1/4茶匙。胡椒。（注意：如果洋葱在焦糖时开始粘住，尤其是在烹饪的尽头，请加一点水，然后用木勺刮擦所有粘在锅底上的棕色钻头。
• Transfer the onions to a bowl. Increase the heat to medium high, and return the skillet to the stove. Add the remaining 1 Tbs. oil and 1 Tbs. butter. Once the butter has melted, add the mushrooms in a single layer and cook, undisturbed, until golden and caramelized, and the pan looks almost dry, about 7 minutes. Lower the heat to low, and season with 1/4 tsp. salt and 1/4 tsp. pepper. Stir and cook until mostly golden and tender, 3 to 4 minutes more.
• Return the onions to the pan, and add the sherry and pepper flakes. Cook until the sherry evaporates (which will happen very quickly), season to taste with salt and pepper, and set aside to cool to room temperature.
• Stir the crème fraîche into the cooled onion-mushroom mixture, and season to taste with lemon juice. Transfer to a serving bowl. Sprinkle with the parsley, and serve at room temperature with the bread or chips.