For the pineapple salsa, cut the red onion and the jalapeno in a small dice. Keep the seeds if you like it very spice or remove them if you prefer it mild. Chop a hand full of cilantro. Core the tomatoes and cut in small dice as well. Season with olive oil, salt, pepper and the juice of one lime. Set aside.
For the avocado crema, slice the avocados in half, remove the pit, and scoop into the food processor or mortar and pestle. Add the shallot and the garlic after cutting it in small dice. Add the sour cream and the juice of one lime. Season with salt and pepper. Run the food processor or mix on the mortar and pestle until smooth. Cover tightly with plastic wrap to avoid browning from oxidation.
Let’s prep the fish: place some flour in a baking tray. Season with salt and pepper. Dredge the fish into the flour and lightly coat each side. Place a sauté pan or cast iron on the stove on medium high heat. Get the pan very hot and drizzle some olive oil. Place the fish on the pan and cook 3-4 minutes per side. Flip and let it rest on a cutting board. Add the tortilla on the pan to quickly warm them up. To assemble the tacos, place a spoonful of avocado crema on the bottom. Cut the two fillets in half and serve one half per tacos. Top with of the pineapple salsa and a small squeeze of lime juice. Garnish with some cilantro leaves.
