1. Chop fish in to small bite sized pieces.
2. Add to a bowl with lemon juice, apple cider vinegar, chilli flakes, garlic and mixed herbs.
3. Leave to marinate for 15 minutes before frying in a little olive oil over a medium heat.
4. Prepare the tacos by tearing cos lettuce leaves from the stalk.
5. Mash some avocado, add some lemon juice and chilli and spread on the leaves.
6. Chop some spring onion, peppers and cucumber and load on top of the guacamole.
7. Finish off by placing the fish bites on top.