Sherry Mushrooms are a delicious tapa or side dish. They're also a fabulous addition to polenta, rice, pasta, steak, chicken, and then some.
Coat a large sauté pan generously with olive oil, and place it over high heat.
Add the the mushrooms in batches, 4 cups at a time, and cook until they have shrunk quite a bit, and are golden brown, stirring from time to time. Remove the mushrooms and add them to a bowl. This should take about 10 minutes per batch. Using some of the oil each time, repeat the process until all of the mushrooms have been sautéed. Add all of the mushrooms back to the pan.
Reduce the heat to low and deglaze the pan with the sherry. Return the heat to high and use a wooden spatula with a flat edge to loosen any mushrooms bits from the bottom of the pan. Mix and sauté until the sherry has evaporated just about completely.
Season generously to taste with salt and pepper. (Here's How to Season to Taste.)