Marinade: Mix together all of the Spice Rub ingredients in a medium bowl. Remove 1 1/2 tablespoons Spice Rub and add this to a large freezer bag along with all of the Marinade ingredients. Whisk together then add fish. Marinate at room temperature for 30 minutes. You will use remaining spices later.Avocado Crema: Meanwhile, make the Avocado Crema by adding all the Crema ingredients to your blender and blending until smooth, scraping sides down as needed. Refrigerate in an airtight container until ready to serve.Pineapple Cucumber Slaw: Add all of the Pineapple Cucumber Slaw ingredients to a large bowl. Toss to combine. Refrigerate until ready to serve.Spice Rub: After 30-60 minutes (no more), remove fish from marinade and pat dry. Mix remaining Spice Rub together with 1 tablespoon olive oil in a small bowl. Rub evenly over fish and let sit for 15 minutes at room temperature.Cook: In a large cast iron skillet, heat 1 tablespoon olive oil over medium high heat. Once very hot, add 1 tablespoon butter. As soon as it melts add fillets and cook approximately 3 minutes per side, or until nicely blackened.Assemble: Remove fish from skillet and break into large pieces. Evenly divide fish among tortillas then top with cheese, Pineapple Cucumber Slaw and Avocado Crema. Garnish with additional lime and hot sauce if desired.