Slice onion into thinnest possible rings; use a mandolin if available. Pour milk in a shallow dish and add the sliced onions. Cover and refrigerate for at least one hour.
In a plastic bag, combine the flour, salt and pepper. Shake to evenly distribute ingredients.
Heat oil to 375° in a deep saucepan. Remove a small handful of onion rings from the milk and shake off excess. Drop into flour, separate rings and shake to coat. Drop a few rings at a time into the hot oil and cook until golden. Remove from hot oil with a slotted spoon and drain on paper towels. Garnish the plate with the crunchy—and tasty—onion strings.
This recipe is from the Old Yarmouth Inn at 223 Route 6A in Yarmouth Port and also appeared in the 2015 November/December issue of Cape Cod LIFE.