Preheat oven to 400. Wash peel and slice plantains into small cubes and transfer into a bowl. Drizzle about a tablespoon of olive oil. Toss to mix and transfer into a greased baking sheet. Bake for 20-25 minutes or until they start to turn brown. Set aside.
Using a hand blender or small food processor, combine all ingredients for shrimp marinade and roughly blend (pulse). Mixture should be chunky. Rinse shrimp, pad dry and transfer into a bowl. Add in 2/3 of the marinade, mix well, seal with saran wrap and refrigerate for about 15 minutes
Meanwhile to prepare salsa, simply combine all ingredients in a bowl. Mix well and adjust for seasoning. Using remaining 3rd of the shrimp marinade add in lemon juice and olive oil. season to taste with salt and black pepper. Set aside. Quickly grill tortillas on open flame for about 15-20 second on each side until slightly charred.
Preheat cast iron skillet. Drizzle some olive oil and grill shrimp for about 3 minutes on each side. Transfer to a serving platter and build tacos as desired. Here I started with the baked plantains, then added the mango salsa, shrimp, purple cabbage and topped with the dressing and a squeeze of lime juice for good measure. Enjoy