In a small mixing bowl, combine the cilantro, jalapeno, ginger, garlic, lime juice, soy sauce, sugar, salt, pepper, and 2 tbsp of olive oil. Stir sauce until well combined. Set aside.

Pat the tuna dry on each side. Season with salt and pepper until the steak is totally covered.

Place a medium skillet over medium-high heat and coat with 2 tablespoons of olive oil.

Place the tuna in the hot oil and sear for 1 minute on each side to form a slight crust. Do not overcook. Tuna should still be mostly pink on the inside.

Pour about half of the cilantro sauce into the pan. Stir or swirl the pan to coat the fish.

Remove tuna from heat and serve on a plate alongside the sliced avocado. Use the remaining cilantro sauce to drizzle over the plate.