Preheat the oven to 425F. In a blender combine the flour, eggs, milk, salt, and pepper and blend for 10 seconds. If the batter needs thinning add 2 tablespoons of water. Melt the butter in a 9-inch ovenproof nonstick frying pan over high heat. Pour in the batter and shake the pan as for an omelet, using a fork only to prevent the batter from sticking around the edges. Lower the heat and cook until the base is firm and golden and the top is still slightly wet. Place the frying pan in the oven and bake for 10 minutes longer, until risen and golden. Serve immediately.
