Preheat oven to 400° F.
Line a baking sheet with non-stick paper and place corn tortillas on it. Brush lightly with olive oil on both sides. Bake for about 5-7 minutes per side, 10-14 minutes total, flipping once. Tortillas should crinkle-up on the sides and just start to turn slightly brown.
Meanwhile, in a small bowl toss tuna (Raincoast Trading doesn't require draining, drain other brandwith zest and juice from 1 lime, garlic, and chopped jalapeño. Season lightly with salt and toss to combine flavours.
In a medium bowl combine pineapple, red bel pepper, avocado, and cilantro. Season lightly with salt.
Layer corn tortillas, tuna, cabbage, and salsa.