Mix together olive oil, melted coconut oil, soy sauce, ginger, and the juice from the one lime. Place the tuna into a shallow dish and pour marinade over. Make sure both sides are coated and marinade for 15-20 mins.
Heat up your griddle pan until smoking hot.
Mix together the diced avo, garlic, chilli, juice of the other lime and coriander in another bowl.
Once the griddle pan is smoking hot, cook the tuna for a minute or two on each side. Remove from the pan, coat in some more olive oil and a squeeze of lime juice and allow to rest for a couple of minutes.
Serve the fish topped with avocado salsa. Season with additional salt to taste and garnish with red pepper flakes (optional).