Roasted Corn and Crab Chowder

6 medium ears corn in husks2 Dungeness or blue crabs, 1-1 1/2 pounds each, cooked2 tablespoons unsalted butter1 small yellow onion, chopped4 fresh thyme sprigs3 bay leaves1 1/2 cups dry white wine, such as Sauvignon Blanc3 cups bottled clam juice or fish stock 3/4 pound red potatoes peeled and cut into 1/2-inch dice 1/2 cup whipping creamSalt and freshly ground black pepper1 tablespoon chives, finely snippedHeat a charcoal grill or use gas grill.Cook the corn 4 inches from the heat, turning occasionally, until the husks are black and the kernels are light brown, about 6-8 minutes. Remove husks and silk, cut kernels from cob and set aside.Clean and crack the crab. Remove meat from body and legs, reserve in bowl. Remove meat from claws and slice; add to bowl. With heavy kitchen shears cut the shells into small pieces and set aside.In a soup pot over low heat melt the butter. Add onions and cook, stirring occasionally, until soft, about 10 minutes. Add crab shells, thyme, bay leaves, wine, clam juice and 1 1/2 cups water. Bring to a boil, reduce heat to low, cover and simmer 20 minutes. Strain and discard shells.Reserve 1 cup corn for garnish. Add remaining corn to crab broth. Simmer until reduced by one-fourth, about 15 minutes. In batches, puree soup in blender, 3 minutes per batch or until smooth. Strain through fine mesh strainer lined with cheesecloth into clean soup pot.Cook potatoes in pot of salted, boiling water until tender, about 10 minutes. Drain and reserve. Add cream, reserved crab meat, reserved corn and potatoes to the pot. Season to taste with salt and pepper. Heat at medium-high until just hot, about 3 or 4 minutes. Garnish with chives, serve immediately with crusty bread and chilled Chardonnay.Serves six.Cook's note: This can be made a couple of days in advance and heated before serving.Nutrition values per serving: 315 calories, 13 g fat (7 g saturated), 33 g carbohydrates, 4 g fiber, 10 g protein, 55 mg cholesterol, 641 mg sodium.