Steps
1. Pat the tuna steak dry and season both sides with salt, pepper, and chili flakes if using.
2. Heat olive oil in a skillet over medium-high heat.
3. Sear the tuna steak for about 2 minutes on each side for medium-rare, or longer if preferred.
4. While the tuna cooks, combine avocado, tomato, red onion, lime juice, salt, and pepper in a bowl to make the salsa.
5. Remove tuna from heat and let it rest for a minute.
6. Plate the tuna steak and spoon the avocado salsa over the top.
7. Garnish with fresh cilantro and serve immediately.