Make the Jerk Marinade. Add the orange zest, thyme, lime juice, ginger, habaneros, scallions, garlic, allspice berries, peppercorns, nutmeg, cinnamon stick, soy sauce, brown sugar, salt, and neutral oil to a blender. Blend until mostly smooth but still slightly textured.
Marinate the Chicken. Coat the chicken thighs completely in the marinade. Cover and refrigerate for at least 4 hours, preferably overnight for deeper flavor. Reserve about 1/2 cup of unused marinade for finishing the chicken later.
Cook the Jerk Chicken. Heat a cast iron skillet over medium-high heat and add a thin layer of neutral oil. Sear the chicken thighs until deeply charred on both sides.
Transfer the skillet to a 350°F oven and cook until the chicken reaches an internal temperature of 165°F.
Remove the chicken and chop it into coarse pieces.
Return the chopped chicken to the skillet with 1/2 cup reserved marinade and 1 tablespoon butter. Cook for a few minutes until the sauce thickens and becomes glossy. Taste and adjust salt if needed.
Prepare the Crispy Plantain Tostadas. Slice the ripe plantains into 1-inch thick coins. Shallow fry the plantain slices in a skillet over medium-low heat until fully cooked but not browned.
Transfer them between sheets of parchment paper and press flat using a tortilla press.
Use a ring mold or round cutter to punch out uniform circles.
Heat oil to 350°F and fry the plantain discs until golden brown and crispy.
Transfer to a rack and immediately season with kosher salt and a pinch of citric acid.
Make the Green Scallion Salsa. Char the scallions under a broiler until lightly blackened. Add the charred scallions, cilantro, lemon juice, neutral oil, garlic, and salt to a container. Blend coarsely with an immersion blender until bright green but still slightly textured. Taste and adjust seasoning.
Char the Soy Glazed Pineapple. Slice the pineapple thin and fan the slices out on a sheet tray. Mix the soy sauce and brown sugar and brush the mixture over the pineapple. Torch the pineapple until caramelized, or broil until lightly charred. Use the same ring mold to cut pineapple rounds that match the size of the plantain tostadas.
Assemble the Jerk Chicken Tostadas. Place a crispy plantain tostada on a plate. Add a round of charred pineapple. Top with chopped jerk chicken. Spoon small dots of green scallion salsa over the top. Finish with fresh cilantro and serve immediately.