Gather your mise en place; get together all of the equipment needed for the recipe and gather your ingredients.

Cut the onion in half and then thinly slice both sides with a knife or mandolin from root to tip.

Cut the lime in half and squeeze all the juice into a bowl.

Pour the lime juice over the onion and add a pinch of salt and sugar. Using clean hands, or tongs, mix everything together really well.

Allow onions to sit for at least 20 minutes before serving. Adjust seasoning as needed.