Lemon and Garlic Roasted Cauliflower Steak

cauliflower steak
1 head cauliflower, cored / 5 teaspoons olive oil / sea salt and freshly ground black pepper /2 shallots, finely minced / 2 garlic cloves, finely chopped /1 cup sliced mushrooms /1/3 cup dry white wine /3 tablespoons fresh lemon juice/1 to 2 tablespoons capers /4 paper-thin slices lemon /1/4 cup minced fresh parsley. Preheat the oven to 425 degrees F. Place the cauliflower on a cutting board, cored side down and cut it into 1/2-inch slices, as if you were cutting a loaf of bread. Arrange the cauliflower slices on a lightly oiled baking pan, and season with salt and pepper to taste. Drizzle with a little olive oil and roast until tender and nicely browned, about 30 minutes, turning once with a large metal spatula about halfway through. Sauce: Heat 4 teaspoons of olive oil in a skillet over medium heat. Add the shallot and sauté for 3 minutes, stir in the mushrooms,and cook 2 minutes longer. Add the wine, lemon juice, and capers and cook, stirring, until the liquid reduces slightly. Just before serving, add the parsley and lemon slices. To serve, arrange the cauliflower on plates and spoon the hot sauce on top. Serve with your favorite greens.