To prepare the marinade, combine in a blender the three types of chiles, garlic, onion, pineapple juice, vinegar, and spices. Blend until smooth and thick. If it is too thick, add a bit of water or more pineapple juice. Strain the mixture to remove any chile skin residue.
Marinate the tuna thoroughly with the mixture, ensuring each piece is well coated. Refrigerate for at least 4 hours, preferably overnight, for deeper flavor.
Cook the marinated tuna in a hot skillet or on a grill over medium-high heat until nicely seared and cooked through.
To serve, place a spoonful of the corn purée on a plate. Top with the grilled tuna. Garnish with pineapple, onion, cilantro and salsa of your choice.