Brush the pineapple slices lightly with 1 tablespoon of the olive oil, then place the pineapple slices on the grill and cook, turning occasionally, until softened slightly and nicely marked by the grill, 2 to 3 minutes per side. Remove from the grill and allow to cool to room temperature. Dice the pineapple slices (discard the tough core portions) and place in a medium nonreactive bowl. Add the red onion, bell pepper, vinegar, jalapenos, lime juice, cilantro and minced garlic. Drizzle with 3 tablespoons of the olive oil and stir well to combine. Season with 1/2 teaspoon of the salt and set aside as you prepare the tuna.
Set a grill pan over medium-high heat. Season the tuna steaks with remaining salt and Essence and brush with the 2 remaining tablespoons of the olive oil. Place steaks on the grill, turning 45 degrees after 2 minutes. Repeat on the other side for an additional 2 minutes or until medium-rare. Remove from heat and set aside. Serve with the Grilled Pineapple Salsa.
Emeril's ESSENCE Creole Seasoning (also referred to as Bayou Blast):
Combine all ingredients thoroughly.
Recipe from "New New Orleans Cooking", by Emeril Lagasse and Jessie Tirsch