Cut all of the onion into really thin slices and then rinse in water. Place the onions in a colander and let drain. Rinse the onion if you want a milder taste and smell.
Finely chop the chili, coriander and ginger.
Cut the celery stalk in half longways, and release the flavors by tapping it with the flat side of the knife. Chop the celery into small pieces.
Boil or bake the sweet potatoes and corn, drain the water after boiling.
Cut off the thinnest part of the fillet, which has a slightly whiter color, and set it aside for the tiger milk. This part is the fattiest and not suitable for ceviche. Fillet the rest of the fish and remove any bones with tweezers. Slice the fish thinly at a downward angle, like sashimi, into pieces of 1.5x1.5 cm.
Rinse the lettuce and let it drain.
Tiger milk:
To make the 'tiger milk', add coriander, garlic cloves, ginger, celery, red onion, fish trimmed from fillet, salt, pepper and lime juice to a blender.
Do not blend them yet. Wait for 5 minutes and then pour in the milk. Blend until smooth. Strain the cream and keep it in a bowl. Discard any solids that remain in the strainer.
Ceviche
Put the chopped trout in a bowl, salt to taste and stir well so that the salt is absorbed.
**SALT THE FISH BEFORE YOU ADD THE SAUCE!**
Add the lime juice and tiger milk, stir well. Add a pinch of chili and a pinch of coriander.
Have a taste – does it need more salt?
Finish with a handful of red onions. Serve directly with salad leaves, sweet potatoes and corn (hominy)
Serve immediately. Fresh ceviche is essential. The lime will continue to 'cook' the fish as soon it touches the fish, and it will overcook and lose its texture if it sits too long, making it unappetizing.