Combine flour, garlic powder, curry powder, marjoram, baking powder, and lemon pepper. Mix well. Slowly add enough flat beer to make a thick batter. Dip halibut in batter and then roll in Panko. Let stand for 2 minutes. Deep fry in 190ºC . fat until golden brown. Drain on absorbent paper and serve with a tartar sauce or a zesty tomato, horseradish sauce for dipping. Serves 3-4.