Standing Rib Roast

Name: Standing Rib Roast
Ingredients: 1 (7-rib) standing rib roast (about 15 pounds); 1 lemon; 2 to 3 cabbage leaves; Beer, for basting (recommended: Sierra Nevada); Coarse salt and freshly ground pepper; Leon's Sauce, recipe follows; 3 tablespoons olive oil; 1/2 cup red wine, such as a dry burgundy; Coarse salt and freshly ground black pepper; 2 tablespoons finely chopped garlic; 1 tablespoon unsalted butter; 8 ounces white button mushrooms, sliced 1/8-inch thick; 10 sprigs curly parsley, leaves chopped; 2 tablespoons demi-glace