In a sauce pan, combine 1 1/2 cups of olive oil, peppers, crushed red pepper, salt, and black pepper. Bring the liquid up to a boil and reduce the heat. Simmer the sauce for 4 minutes and remove from the heat. Stir in one tablespoon of garlic. With a hand held mixer, puree the sauce until smooth. At this point, allow the sauce to sit for 1 week under refrigeration before serving. Stir in the cilantro and kosher salt. Marinate the mackerel in the piri piri for 3 to 4 hours, under refrigeration. Dredge the mackerel in the cornmeal. In a large saute pan, heat the 1/4 cup of the olive oil. When the oil is hot, gently place the mackerel in the hot oil. Fry the fish for 3 to 4 minutes on each side. Remove the mackerel from the oil and drain on a paper-lined plate. Season the fish with salt and pepper. In a saute pan, heat the remaining 2 tablespoons of olive oil. When the oil is hot, add the spinach and 2 teaspoons of garlic, saute just until the spinach starts to wilt, about 1 to 2 minutes. Season with salt and pepper and remove from the heat. In a blender, combine the extra-virgin olive oil, stock, the 2 tablespoons of garlic, shallots and parsley together. Puree until smooth. Strain the sauce through a fine mesh strainer. Season with salt and pepper. To assemble, spoon a small pool of the sauce in the center of the plate and around the rim. Mound the spinach in the center of the sauce. Lay the fish directly on top of the greens. Garnish with parsley.