Lightly brush a large griddle or BBQ with a small amount of olive oil and leave over a flame to heat up
Clean the tuna and use one of the limes and some salt to season it
Prepare the marinade by pouring the olive oil and vinegar into a bowl, crush and add the chillies, garlic, and ground coriander
Chop all the herbs and add them to the other ingredients
Add the tuna to the bowl, ensuring it is completely covered by the mixture
Allow the fish to marinate for a couple of minutes, then place it on the griddle, sprinkling any leftover herbs on top
Cook for 1 – 2 minutes on each side to sear the tuna, or a few extra minutes for a well-done result
This tuna is perfect served with a couscous salad, potato salad, or spicy rice