Thin Crêpes and Naleśniki

Whisk 250 g flour with three eggs, then gradually add 500 ml milk, a pinch of salt and two tablespoons of melted butter until smooth. Rest it 30 minutes. It should be as thin as heavy cream. Heat a crêpe pan or 24 cm nonstick pan over medium-high and wipe it with butter. Pour in a small ladle while turning the pan so the batter coats the base thinly. Flip after about a minute when the edges lift and the underside has brown spots. In Poland, naleśniki are filled with sweet twaróg and folded into squares.