Pickled Red Onion Recipe 1 red onion thinly sliced 3/4 cup Cider Vinegar 3 Tablespoon Sugar Pinch Salt Pinch Ground Black Pepper Pinch Crushed Red Pepper Bring Vinegar, Sugar, and seasonings to boil. Add red onion and cook for 30 seconds. Remove from heat and allow to cool. Place in jar and refrigerate for up to a month. Malcom …