Cover a frying pan on a thin layer of oil and bring the flame to medium heat.
Lightly fry the zucchini, chillies, onion and garlic; remove when starting to get brown and place in a blender.
Add the lime juice, coriander, veggie stock, olive oil, avocado and salt. Blend until you have achieved a smooth consistency.
Place in a sealed container and store in the fridge until ready serve.
In a bowl, mix all the ingredients for the garnish.
Prepare the batter by mixing all the ingredients in a food processor or blender. Add the mineral water slowly until you achieve a thick consistency for the batter.
Place the batter in a mixing bowl, and the additional corn flour on another. In a frying pan or fryer, add enough oil to cover submerge the fish and heat the oil at medium temperature.
Grabbing one piece of fish at a time, toss it on the flour, then cover on batter and put it in the hot oil. Place the battered fish on paper towels to absorb the extra oil.
On a very hot frying pan, place the corn tortillas on each side until soft and floppy, wrapping them in a tea towel as you go to stay warm.
Assemble the tacos by putting a piece of fish on each tortilla, then garnish followed by salsa on top.