Ingredients  : 

3 cups water
2 red onions, thinly sliced into half-moons
3/4 cup white wine vinegar
1 teaspoon sea salt
1 teaspoon white sugar
5 black peppercorns

Direction   : 

Boil water in a saucepan.

Stuff slices of onion into a pint-size Mason jar.

Add some boiling water on top of onions. Leave to rest for ten seconds.

Pour water out through a mesh strainer, maintaining the onions in the jar.

Repeat 2 more times to cook the onions a bit.

Measure out vinegar into a bowl. Mix in sugar and salt until
dissolved.

Pour in peppercorns and add the vinegar solution on
top of onions. Seal and shake thoroughly.

Chill for at least an hour prior to serving to allow flavor to
develop.

Nutrition Information   : 

Calories: 15 calories;
Total Fat: 0
Sodium: 226
Total Carbohydrate: 3.5
Cholesterol: 0
Protein: 0.4