Step 1

Cut the onion in half, slice very finely (a mandolin is very helpful with this part) and place in a bowl

Step 2

Sprinkle with 1 tablespoon salt and a squeeze of lime juice, let rest for about 10 minutes

Step 3

Cover the onions with lukewarm water and let rest for another 10 minutes

Step 4

Rinse and drain the onions

Step 5

Add the lime juice, salt and the oil, and mix well.

Step 6

Cover the onions and place in the fridge, the onions will start to turn pinkish after about 3 hours, and will turn very pink if left overnight. Taste again before serving and add salt if needed.