SPICY MANGO SALSA
In a large ceramic bowl combine the mangoes, onions, jalapeno, ginger, Sriracha, and lemon juice, and blend well. Season with salt and pepper. Use or refrigerate.
In a mortar, crush together the fennel seeds, coriander seeds, mixed peppercorn, sea salt, and regular pepper until all seeds are crushed.
Place the rub on a plate, add the yellowfin tuna and coat them well on both sides.
Meanwhile, heat to high heat a non-stick skillet. Once the skillet is hot, rub some olive oil over the yellowfin tuna and place the oiled side into the pan. Sear on high for 1 ½ to 2 minutes per side.
Remove from the skillet when done: they should be pink in the middle, sprinkle more olive oil over it, and gently squeeze lemon over each tuna.