Source: https://www.loveandlemons.com/pickled-red-onions/

2 small red onions

Slice thinly and divide between two 16 ounce mason jars

2 cloves garlic
1 tsp peppercorns

Add to jars

2 cup white vinegar
2 cup water
0.33 cup sugar
2 tbsp salt

Heat over medium

Stir until dissolved, about 1 minute

Let cool, then pour over the onions

Cool onions for at least 1 hour if thin, longer for thicker

They should be bright pink and tender