Place the cauliflower into the liquid and cover tightly with foil. Carefully transfer to the oven and let bake for approximately 30 to 45 minutes. Ultimately, the time will depend on how thick the "steaks" are.
Test the cauliflower periodically. When a knife goes in somewhat easily, it is done. The cauliflower should be cooked through, but still a bit firm. If it's too soft, it will fall apart during frying.
Meanwhile, to make the pistou, combine the oranges, juice of remaining lemon, olives, garlic, parsley, raisins and 2 tablespoons olive oil. Gently toss, and set aside.
To finish the dish, remove the cauliflower from the oven and carefully remove the foil. Remove the cauliflower from the liquid and place on a plate lined with paper towel. Blot the top of cauliflower, as well. This step helps to ensure a nice golden crust.
Next, heat a large fry pan, or cast iron skillet, over medium heat. Once hot, add remaining 2 tablespoons oil, followed by the cauliflower. Let the cauliflower cook for about 4 to 6 minutes, or until golden brown on each side. Try not to fiddle with the pieces too much, otherwise the cauliflower will start to fall apart.
Once done, transfer to a serving plate and top with half of the pistou. If desired, drizzle some of the pistou juice around the plate and finish with freshly ground black pepper, if desired.