Baked mushroom caps are a tender and buttery delight. You can use any variety of edible mushroom to make your baked caps, but button mushrooms, shiitake mushrooms, portobello mushrooms or crimini mushrooms are the best choices because they have tender caps that bake well. The mushroom caps are typically baked in butter but you can substitute olive oil for a more healthy dish, if you prefer. Leave the mushroom caps plain or season them with herbs such as oregano and sprinkle Parmesan cheese over them.
Preheat the oven to 350 degrees Fahrenheit.
Gently wipe the mushrooms with a damp cloth or paper towel to remove the dirt. Don't submerge mushrooms in water or they will become slimy.
Trim the stems off the mushrooms and discard them.
Lay the mushrooms, gill-side up, on a baking sheet. If you have a lot of mushrooms or a small pan, it is fine to layer them.
Cut the butter into small pieces, if you are using it, and sprinkle it over the mushrooms. If you are using olive oil instead of butter, drizzle it over the mushrooms.
Sprinkle the oregano and Parmesan over the mushrooms.
Bake the mushrooms for 20 to 30 minutes or until the mushrooms are tender enough to pierce easily with a fork.
Serve the mushrooms hot.