Fish Chowder with Root Vegetables

Name: Fish Chowder with Root Vegetables
Ingredients: 4 slices bacon; 1 tablespoon unsalted butter; 2 stalks celery; 4 scallions; 1/2 large rutabaga (about 1 1/2 pounds), peeled and diced; 2 medium Yukon Gold potatoes (about 12 ounces), peeled and chopped; 4 to 5 sprigs thyme; Kosher salt and freshly ground pepper; 1 8-ounce bottle clam juice; 1 1/4 pounds skinless cod, haddock, hake or pollock fillets; 3/4 cup half-and-half or heavy cream; 1 1/2 cups oyster crackers or 4 crusty dinner rolls, for serving