Drain and mix the tuna with the capers, olives, sun-dried tomatoes, herbs and zest. Divide the filling between the fish, covering only half of it, flip over to cover the filling. Wrap the fish with the lemon leaves and secure with cocktail sticks. Place the fish on a roasting tray, drizzle with extra virgin olive oil, season with salt and pepper. Squeeze lemon juice on top and bake in a moderate oven for approximately 10 minutes. Fry the anchovies in a sauté pan until creamed add chopped garlic, butter and spinach, cover and allow spinach to wilt. Finish with the cream. Reduce together the tomato passata, vegetable stock, honey and balsamic vinegar until syrupy.