Root Vegetable And Mushroom Pie With Rosemary Biscuit Topping

Name: Root Vegetable And Mushroom Pie With Rosemary Biscuit Topping
Ingredients: 6 cups water; 2 tablespoons vegetarian bouillon base; 2 very large carrots, peeled, quartered lengthwise, cut crosswise into 1/2-inch pieces; 1 large celery root (celeriac), peeled, cut into 1/2-inch pieces; 2 large parsnips, peeled, quartered lengthwise, cut crosswise into 1/2-inch pieces; 1 large rutabaga, peeled, cut into 1/2-inch cubes; 1 turnip, peeled, cut into 1/2-inch cubes; 1 ounce dried porcini mushrooms,* broken into 1/2-inch pieces, rinsed; 3 tablespoons butter; 3 cups chopped onions; 4 large garlic cloves, chopped; 1/2 teaspoon minced fresh rosemary; 1/2 cup all purpose flour; 1/4 cup heavy whipping cream; 2 tablespoons imported dry Sherry; 1/4 cup chopped fresh Italian parsley; 2 1/4 cups unbleached all purpose flour; 1 tablespoon baking powder; 2 teaspoons minced fresh rosemary; 1 teaspoon salt; 6 tablespoons (3/4 stick) chilled unsalted butter, diced; 1 1/3 cups (or more) chilled buttermilk