Clean the mushrooms with a paper towel or damp cloth. Trim any tough or soft ends, and cut larger mushrooms into halves or quarters if necessary.

In a bowl, combine the flour, salt, pepper, paprika, garlic powder, and onion powder. Toss the mushrooms with about 1/4 of the flour mixture until they’re lightly coated.

In a separate bowl, whisk together the soda water, buttermilk, and egg. Sift the remaining flour into this wet mixture, stirring until smooth and lump-free.

Set up a breading station. Place the panko breadcrumbs in one bowl, and set it next to the flour-coated mushrooms and batter bowl.

Heat the oil in a deep fryer or large saucepan to 350ºF. Make sure the oil is at the right temperature by testing it with a wooden spoon—if bubbles form immediately, it’s ready to fry.

Dip the mushrooms into the batter, allowing the excess to drip off, then coat them in panko breadcrumbs.

Fry the mushrooms in batches for 3-5 minutes, turning occasionally, until golden brown and crispy.

Place the fried mushrooms on paper towels to drain excess oil. Serve them hot, garnished with parsley, as a delicious appetizer or snack with your favorite dips!