Ceviche with Rocoto (extra-spicy)

1½ lb (600g–1kg) fish and/or seafood (Recommended: Grouper, Red Snapper, or Sole)
½ cup red onion, julienned
1 package Natural Gourmet Ceviche Juice with Rocoto Chili Flavour (enough for 1kg of fish)
9 oz (260ml) cold water
Optional Accompaniments:
Boiled sweet potatoes
Cooked corn
Toasted corn snacks (e.g. Cancha Chulpe, Roasted Mountain Corn, Corn for Toasting)

In a bowl, mix the Rocoto Ceviche Juice with 260ml (9 oz) of cold water until fully dissolved.
Cut the fish and/or seafood into 2cm cubes.
Pour the prepared ceviche juice over the fish.
Let it sit for about 3 minutes.
Add the julienned onion, mix gently for 30 seconds, and enjoy!