Adapted from allrecipes.com
cup all-purpose flour
teaspoon garlic salt
pound button mushrooms, quartered
cups oil for frying, or as needed
In a medium bowl, stir together the flour and garlic salt. Mix in egg and water until smooth. Heat the oil in a large deep skillet over medium-high heat. Test to see if oil is hot by frying a drop of batter. If it sizzles and floats to the top, the oil is ready. Dip mushrooms into the batter and then place in the hot oil. Fry a few at a time so they are not crowded, until golden brown, 3 to 5 minutes. Remove from oil with a slotted spoon and drain on paper towels.