Preheat the oven to 375 degrees F. Season the fillets with Essence. In a large nonreactive ovenproof skillet over high heat, add the oil. When the oil is hot, add the fish fillets and sear the first side, for about 1 minute. Flip the fillets with a spatula and add the eggplant, tomatoes, onions, and basil. Season with salt and black pepper. Stir in the tomato puree and 1/2 cup of the stock. Bring the liquid to a boil. Remove the skillet from the burner, place in the preheated oven and roast for 25 minutes. Remove the pan from the oven and place on a burner over high heat and cook for 5 minutes longer. Combine the potatoes, saffron threads and 6 cups of chicken stock. Season the liquid with salt and pepper. Bring the liquid to a boil and reduce the heat to a simmer. Cook the potatoes until firm-tender about 12 to 14 minutes. Remove the pot from the heat and allow the potatoes to sit in the broth for 2 to 3 minutes to soak up the flavors. Remove the potatoes with a slotted spoon and set aside, keeping warm. Allow the broth to cool and then refrigerate or freeze it for later use. Heat the oil in a large pot over high heat. Season the flour with Essence. Dip the onions in the egg wash and toss in the seasoned flour. When the oil is very hot, fry the onions in batches until golden and crisp, for about 2 to 3 minutes. Remove with a slotted spoon, drain on paper towels, and sprinkle with salt. To serve, spoon the potatoes in the center of the plate. Lay the fillet on top of the potatoes and spoon over some of the sauce. Garnish each plate with the onion crisps.
Combine all ingredients thoroughly.