1. Finely mince 2 of the garlic cloves and 2 of the anchovies. Combine in a mortar and pestle with lemon zest and 1?4 tsp. of the pepper and mash into a smooth paste; alternatively, mash the mixture in a bowl with the back of a spoon. Add 1 Tbsp. of the olive oil and stir to make a paste. Smear the tuna steaks evenly with the paste, cover,and refrigerate for 1 to 4 hours.
2. When ready to cook the tuna, spread the flour in a shallow dish and dredgethe tuna evenly, tapping to shake off any excess. Heat 1 Tbsp. of the oil in a large saucepan over medium-high heat. Add tuna and cook, without moving it, until the bottom is browned, about 3 minutes. Turn over and continue to cook, again without moving it, until the second side is browned, about 3 more minutes. Remove tuna from the pan and set aside. Depending on the size of the steaks, you may need to do this in batches.
3. Heat remaining 1 Tbsp. oil in the same pan. Add onions, reduce heat to medium,and cook, stirring frequently, until soft and lightly browned, about 7 minutes. Mince remaining 2 garlic cloves and 2 anchovies and add with remaining 1?4 tsp. pepper and cook, stirring until fragrant, about 40seconds. Add wine, increase heat to high, and simmer, scraping bottom of pan with a wooden spoon to loosen and dissolve any brown bits, until reduced by about half,about 6 minutes.
4. Add thyme sprigs, parsley stems, celery rib, and bay leaves to the pan, along with tomatoes. Return to a simmer, and cook, stirring occasionally to blend flavors, about 3 minutes. Add tuna, baste with some of the tomato mixture, reduce heat to low, and bring to a gentle simmer. Cover pan andcook, basting tuna occasionally, until it is very tender but not falling apart, about 80 to 90 minutes.
5. Transfer tuna to a serving platter and tent loosely to keep warm. Use a fork to remove the herb sprigs, celery, and bay leaves from the sauce. Increase heat to medium-high and simmer, stirring constantly to concentrateflavors and reduce slightly, about 5 minutes.
6. Add 2 Tbsp. of the chopped parsley,stir, and top tuna with sauce. Sprinkle with remaining parsley, and serve immediately.
Source: Hannaford fresh Magazine, November - December 2010