Peel 4-6 large onions, slice 1/4 inch thick and separate rings. Beat 3 eggs lightly. Add 3/4 cup flour, 1/2 cup milk and 3/4 teaspoon salt, and stir the batter until it is the consistency of heavy cream. Dip the rings in the batter, a few at a time, and fry in hot oil (375 degrees) until golden brown. Drain on absorbent paper and sprinkle with salt just before serving.