1 cup apple cider vinegar
1 cup water + more for boiling
3 TBSP. packed brown sugar
1 tsp. salt
1 tsp. whole peppercorns
4 red onions, sliced thinly
Slice onions into "rainbow" slices. Put water on to boil. While water is boiling, in a large bowl, mix vinegar, 1 cup of water, brown sugar, salt, peppercorns. Stir until sugar is dissolved and set aside. Place sliced onions in a colander in sink and pour boiling water over them. They will wilt just a bit. Allow onions to drain well and then remove them to a quart jar or two pint jars. Pour vinegar mixture into the onion jar(s) until onions are covered. Seal jars and allow to sit at room temperature for 3-6 hours. Place in refrigerator overnight and enjoy the next day. They will "keep practically indefinitely."
Serve on salads, beans, sandwiches, pasta, rice, pizza....
Recipe from Salads by Mollie Katzen