1 medium-large red onion ½ cup freshly squeezed lime juice 1 teaspoon kosher salt 1 teaspoon sugar
Slice onion in half from root to stem. Peel the outer skin and discard. Slice off the root and stem, then thinly slice each half of the onion.
Add the onions, lime juice, salt, and sugar to a mixing bowl and stir well.
Refrigerate and stir well again after one hour. Store covered in the refrigerator until ready to use.