1) Peel the onions.
2) Slice them into round 1/4-inch slices and separate into individual rings.
3) In a bowl, beat in the egg with milk and salt.
4) Dip the onion rings in batches into the egg mixture to coat every inch of its surface.
5) In a paper bag, add in the flour. Drop the egg-coated onion rings into the paper bag, once again in batches.
6) Shake the paper bag well to coat all the rings with the flour.
7) Repeat the same with all the onion rings.
8) In a deep frying pan, add in lard. Once heated, add in the onion rings. Fry till they turn a light golden brown on both sides.
9) Transfer onto paper towels to drain off excess oil.
10) Serve the Onion Fritter Rings hot, with tartar sauce on the side, if desired.