PRE-SLICED MUSHROOMS. It’s always best to buy whole mushrooms and to slice your own. It’s not difficult, nor does it take much time. This way you control the thickness, and if you want to cube or quarter them, you have that option. More often than not, groceries slice them too thin, then keep them too long on the produce shelf, whereby they turn brown. Brown mushrooms smell and taste fishy – an aroma and taste you don’t want to spoil a dish over.
I always wash my mushrooms, unlike T.V. chefs who keep telling you not to. Wiping them with a towel is ridiculous, since most towels have been used for other stuff. Washing them is quicker than wiping each one down. They dry quickly in a colander and you don’t have any residue from what they were grown in enter your recipe.