To make the avocado crema, combine all the ingredients in a food processor. Blend until smooth, then check for seasoning and add more if required. Spoon the crema into a bowl, then cover and store in the fridge until required.

To make the marinade for the fish, add all the ingredients to a bowl, stir well, then cover and leave for at least 30 minutes.

Preheat the oven to 425F. Transfer the pieces of fish onto a lined baking sheet, and discard any remaining marinade. Season the fish with salt and pepper, then roast for around 10 minutes or until the fish has cooked through.

For hard tacos, drape the tortillas over the bars of your oven grill racks until they are crispy. For soft tacos, heat the tortillas in the microwave for 30 seconds. Load up the the tacos with the slaw and fish, then finish with the avocado crema.