Preheat oven to 400 degrees F .

Remove any dirt that may be clinging to the caps of your mushrooms , but do not get them wet , Trim them .

Toss the caps in a bowl with a few tablespoon of olive oil , mix it .

Then add a few tablespoons more oil and toss again , add salt and toss one more time.

Lay out the caps on the baking sheet .

Bake for 25-40 minutes , keep check on them flip them halfway through cooking .