For the black bean salsa: 1) Toss the tomatoes, spring onions, black beans, coriander, jalapeno, and the lime juice in a medium bowl. Add some salt to taste and set aside to let the flavors develop.
For the mahi-mahi: 1) Place the soy sauce, orange juice, ketchup, honey, lime juice, garlic, basil, oregano, and pepper in a small bowl and whisk until the honey is completely dissolved. Pour the marinade into a re-sealable plastic bag with the fish fillets and marinate in the refrigerator for 30 to 45 minutes.
2) Oil your barbeque grates with rapeseed oil to help prevent sticking. If using a gas barbeque, preheat the barbeque to high. Griddle the fish for 5 to 6 minutes on a side, turning carefully using a turner large enough to support the entire piece of fish, until browned, firm and flaky.
3) Serve with the black bean salsa and lime wedges.
Indoor Variation: Heat the griddle pan to a high heat. Remove the fish from the marinade and pat dry with paper towels. Brush both sides of the fish with oil and place on the hot grill pan. Oiling the fish instead of the pan will limit the amount of smoke. Cook for 5 to 6 minutes on each side.