- 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
- 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
- 6 tablespoons (3/4 stick) chilled unsalted butter, diced
- 1 1/3 cups (or more) chilled buttermilk
Bring 6 cups water and bouillon base to boil in large pot over medium-high heat, stirring to dissolve bouillon. Add carrots and next 5 ingredients. Simmer until vegetables are tender, about 7 minutes. Drain; reserve vegetables and broth.
Melt butter in same pot over medium heat. Add onions; sauté until beginning to brown, about 10 minutes. Mix in garlic and rosemary; stir 2 minutes. Add flour; stir 1 minute. Gradually whisk in reserved broth, then cream and Sherry. Cook until sauce is thick and reduced to 4 cups, whisking often, about 8 minutes. Mix in reserved vegetables and parsley. Season with salt and pepper. Transfer filling to buttered 13x9x2-inch baking dish. DO AHEAD Can be made 2 days ahead. Cover with foil; chill.
Preheat oven to 400°F. Bake filling, covered, until bubbling, about 50 minutes. Meanwhile, prepare biscuits.
Stir first 4 ingredients in large bowl to blend. Add butter. Using fingertips, rub in butter until mixture resembles coarse meal. Gradually add 1 1/3 cups buttermilk, tossing with fork until dough is evenly moistened and adding more buttermilk by tablespoonfuls if dry.
Drop biscuit dough atop hot filling by heaping tablespoonfuls; sprinkle with pepper. Bake uncovered until tester inserted into center of biscuits comes out clean, about 45 minutes. Cool 15 minutes.