There is no need to peel mushrooms. The only trimming they may need is the stem end, if it's dry, or the tough stem portion of Shiitakes or the root of the Portabella. All other mushroom stems may be prepared along with the caps.

Mushrooms can be sliced thick or thin, cut in quarters, coarsely or finely chopped using a sharp knife. For slicing or chopping large quantities, use a food processor with the slicing or wing blade attachment.

If a recipe calls for just caps, twist stems loose or separate them from the caps with the tip of a knife.