Season both sides of each tuna steak with the Creole seasoning.
Heat a large sautÈ pan over high heat for 2 minutes. Sear the steaks for 1 minute and turn over. Add 1 tablespoon of the butter, the onions, salt, and cayenne. Cook for 1 minute and remove the steaks.
Add another tablespoon of the butter to the pan and continue to cook the onions for 3 minutes, stirring. Add the tomatoes, olives, garlic, green onions, herbs, and black pepper and cook, stirring, for 2 minutes. Add the stock and bring to a boil. Reduce the heat to medium-low and simmer for 1 minute. Return the tuna steaks to the pan and add the remaining tablespoon butter. Cook for 1 minute, basting the steaks with the sauce. Remove from the heat.
To serve, stack fried parsnips on top of each tuna steak on individual plates and serve with the creamed potatoes.
Yield: 4 servings