Check your avocado is ripe before starting this recipe. (To speed up the ripening process, put the avocado in a paper bag and loosely close, then leave on the kitchen bench for a day or two. Add a banana to the bag to make the avocado ripen faster.) Coarsely chop the tomato and avocado. Crush or finely chop the garlic.
Step 2 — Season fish
Put the garlic, cumin and coriander spice blend and 2 tsp olive oil in a shallow dish, season with salt and pepper and stir to combine. Add the fish and turn to coat.
Step 3 — Cook fish
Heat 2 tsp olive oil in a medium frypan over medium heat. Cook the fish for 3½-4 mins each side until browned and cooked through (to test the fish, flake it with a fork; if it comes apart easily, it is cooked). Remove from the pan.
Step 4 — Make salsa
Meanwhile, put 2 tsp extra virgin olive oil and 1 tsp red wine vinegar in a large bowl and season with salt and pepper. Add the tomato and avocado to the dressing and stir to coat.
Step 5 — Warm tortillas
Put the tortillas on a plate, slightly overlapping, and microwave for 30 secs or until warmed through. (Or, warm the tortillas, in batches, in a frypan over medium-high heat for 30 secs each side.)
Step 6 — Get ready to serve
Flake the fish into chunks. Spread the tortillas with the aioli. Divide the spinach, fish and some of the salsa among the tortillas. Serve with the remaining salsa.