Do yourself a favor and go beyond the button mushroom. There is nothing wrong with a button mushroom. There is however more depth and flavor in other varieties of mushrooms that are probably available at your local supermarket. The mistake that people often make that kills the mushroom’s chance at being delicious is they wash them. Washing mushrooms waterlog them and mess with the structure of a tremendous ingredient.
For this dish remember to season the mushrooms after cooking. A little olive oil is all you need to start. Cut your mushrooms into the desired size and add leeks (wash leeks well) parsley, and garlic. Send to the oven at 400 degrees.
It takes approximately 20 to 25 minutes and be sure to stir them halfway through. Side note know your oven since oven times and temps vary from one oven to the next.When the mushrooms have reached their desired doneness pull them out of the oven and season. I added salt, garlic butter and served. The mushrooms were fan freaking tastic. I served them with a juicy steak.