Ceviche de Pescado

1. Cut the fish into cubes and place in a container. Marinate it in the refrigerator with a little bit of onion and enough lime juice to completely cover the fish.
2. After 30 minutes, remove the fish, discard the lime juice it was marinated in (this is key to being able to keep it until the next day without it getting mushy). Mix the fish with the rest of the ingredients: tomato, more onion, mango, and quinoa. The next day, when you are ready to eat it, add more lime juice!