Begin by preparing the Spicy Tomato Relish.
In a medium bowl, combine diced tomatoes, chopped red chili, and red onion.
Drizzle with olive oil and lemon juice.
Add fresh coriander (cilantro) and salt, mixing until well combined.
Set aside to let the flavors meld.
Preheat your grill to medium-high heat.
While the grill is heating, lightly brush each tuna steak with olive oil.
Season both sides with salt and black pepper.
Once the grill is hot, place the tuna steaks on the grill.
Cook for about 3-4 minutes on each side. This will give you a medium-rare center. If you prefer your tuna more cooked, grill for an additional minute or two on each side.
Remove the tuna from the grill and let it rest for a couple of minutes.
Plate each tuna steak and generously top with the Spicy Tomato Relish.
