How to Bake Portabella Mushrooms
- 1). Wash the portabella mushrooms under running water and dry thoroughly. Remove the stems by pulling them gently. Discard the stems. Score the underside of the mushrooms with a knife several times, so that the marinade will be able to permeate into the portabellas.
- 2). Prepare the marinade. In a mixing bowl, combine balsamic vinegar, minced garlic, thyme, sage, rosemary, salt and pepper. Slowly drizzle in ¼ cup olive oil, whisking as it is added to create an emulsion.
- 3). Put the mushrooms in the bowl with the marinade and allow them to sit in the fridge for at least 1 hour, or up to two days.
- 4). Preheat the oven to 350 degrees Fahrenheit when you are ready to bake the mushrooms. Line a cookie sheet with aluminum foil to keep the mushrooms from sticking to your pan.
- 5). Lay the mushrooms out on the foil-covered cookie sheet. Pour the marinade over the mushrooms, and bake in the oven for 10 minutes. Turn the mushrooms and cook them for ten more minutes. Remove from the oven and serve either whole or sliced.
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