Mussel Chowder

Name: Mussel Chowder
Ingredients: 1 tablespoon unsalted butter; 2 large shallots, finely diced; 1 clove garlic, minced; 2 small celery ribs, sliced; ½ cup dry white wine; 2½ cups water, seafood broth, or a combination; 1 bay leaf; 1 handful thyme stems; 2 large yukon gold potatoes, peeled and diced; 3 pounds mussels in their shells; 1 cup whole milk; 2 tablespoons toasted all-purpose flour (see note #1); 1 cup heavy cream; Fine sea salt; Freshly cracked black pepper