Beat together the egg, buttermilk, grill seasoning, and 1/2 cup of flour in a large bowl until smooth. Add the beef, and toss until well coated. Cover with plastic wrap, and place into the refrigerator to marinate at least 2 hours.
Sift 2 1/2 cups flour with the garlic powder, salt, and pepper into a large bowl. Remove steak strips from buttermilk batter and allow excess to drip off. Dredge each piece with seasoned flour and place onto a baking sheet. Place in the freezer and freeze until firm, 1 hour to overnight.
Heat oil to 370 degrees F (185 degrees C) in a deep fryer or cast iron skillet.
Drop a few frozen steak pieces into the hot oil and fry until golden brown on the outside, about 5 minutes. Do not overcrowd the frying oil, and do not allow the steak strips to thaw before they are fried. Once golden brown, remove to drain on a paper towel-lined plate.