Bring the salmon to room temperature. (This is important so that the fish cooks properly. You can also brine it, which helps to make sure there is no “white stuff” that oozes when cooked. In a large shallow dish, whisk 4 cups room temperature water and 3 tablespoons kosher salt until dissolved. Place the salmon in the water and wait for 15 minutes.)

Mix the cumin, chili powder, smoked paprika, and garlic powder in a bowl. Pat the salmon dry with a clean towel. Rub it with a drizzle of olive oil and sprinkle it with the ¾ teaspoon kosher salt divided between the filets, then the mix of seasoning.

Heat a large cast iron or stainless steel skillet (not non-stick*) over medium high heat and add the butter and olive oil. When the butter is melted, add the salmon skin side up and cook for 2 to 3 minutes until cooked about halfway to the center of the thick part of the salmon.

Flip the salmon. Tilt the pan down slightly and quickly spoon the pan juices over the top of the fish a few times. Drizzle with the lime juice and spoon the pan juices a few times again. Cook for 2 to 5 minutes, depending on the thickness, until just tender and pink at the center (the internal temperature should be between 125 to 130°F in the center)**. Remove from the heat and allow to sit for 5 minutes. Then flake the salmon into large pieces with a fork. Taste and add additional pinches of salt if necessary.

Make the Avocado Sauce.

Make the pineapple pico (optional): Finely chop 1 cup pineapple rings. Then mix it with ½ cup pico de gallo, 1 tablespoon chopped cilantro, and a pinch of salt. (Or, use 1 cup pico de gallo to keep it simple!)

Warm the tortillas: Warm and char the tortillas by placing them on an open gas flame on medium for a few seconds per side, flipping with tongs, until they are slightly blackened and warm. (See How to Warm Tortillas.)

Serve: Layer the tacos with salmon, salsa and avocado sauce. Top with minced red onion and chopped cilantro and serve.