Trim the stems from the mushrooms, and wipe mushrooms with a damp cloth.
PREPARE BREADING STATION, using Tupperware-like containers that have lids.
Container #1: Flour, salt, pepper, onion powder, garlic powder, paprika.
Container #2: egg and buttermilk.
Container #3: Italian bread crumbs and Parmesan.
Working in batches, coat mushrooms in flour mixture, then egg wash, then bread crumbs mixture.
Add enough oil to a heavy-bottomed skillet for about ¼" depth, and heat.
I use a 10" skillet, and fry the mushrooms in 2 batches.
I test the heat of the oil by adding a mushroom stem...when it bubbles immediately and floats, the oil is ready.
Add mushrooms cap side down. Fry for 2-3 minutes per side, until golden brown.
As soon as they're done, transfer to paper towels to drain.
Immediately sprinkle mushrooms with Kosher salt.
Serve immediately.
