Beat the eggs in a bowl with a pinch of salt, then using a whisk fold in the sieved flour and add the milk pouring slowly. Leave the mixture aside for 30 minutes. Heat a non-stick frying pan, rub with a little butter and pour over enough pancake batter to thinly cover the bottom of the pan. Cook the pancakes until bottom begins to curl upwards, flip over carefully and finish cooking. Place a small amount of the previously sautéed asparagus tips and gorgonzola on each pancake and fold over. Arrange the pancakes in a greased baking dish and cook for 2 minutes. Serve immediately.