Tear the mushrooms in half lengthwise.
Dip the mushrooms in the flour coating, shaking off excess; Dip in the batter and shake off excess, roll in the crumb coating, and place on a plate.
Heat canola or sunflower oil in a medium 24-26 cm skillet; the oil should reach about half the height of the mushrooms (no need to deep fry)
Transfer 4-5 mushrooms to the hot oil and fry on both sides until nicely golden (about two minutes on each side). You can use tongs. Remove and place on paper towels to absorb excess fat, and repeat with the rest of the mushrooms.