Quick Pickled Red Onions Recipe

0 Slice the top and bottom off the onion and then slice onion in half, from top to bottom. Remove the outer peel. Lay the cut surfaces of the onion onto the cutting board, and then slice into half moons using a very sharp knife. 
3 Add the sliced onions, chopped garlic cloves and red pepper flakes to a glass jar- I like to use a pint mason jar.
4 In a medium saucepan, whisk together apple cider vinegar, white vinegar, sugar, and salt. Place over medium-high heat and bring mixture to a boil. Whisk until sugar and salt dissolve, then remove pan from heat.
5 Carefully pour liquid over the sliced onions and gently stir to combine. Let mixture cool at room temperature. Cover tightly with a lid and store in the refrigerator until chilled. This recipe is for refrigerator pickling only and needs to be stored in a refrigerator!