In a small bowl, combine sour cream, mayonnaise, parsley, dill, garlic powder, onion powder, salt, and black pepper. Mix well and refrigerate the dip while preparing the mushrooms.
In a medium bowl, whisk together eggs and milk. In another bowl, mix flour, paprika, garlic powder, onion powder, salt, and black pepper.
Dip each mushroom into the egg mixture, then coat evenly with the seasoned flour.
Heat oil in a deep skillet or pot over medium-high heat. Once hot, fry mushrooms in batches until golden brown and crispy, about 4–5 minutes per batch.
Remove and drain on paper towels. Serve hot with chilled ranch dip.