Smoked Fish Chowder

Name: Smoked-Fish Chowder
Ingredients: 2 Tbsp. unsalted butter; 4 oz. bacon, chopped; 1 medium onion, chopped; 1 medium leek, halved lengthwise, thinly sliced crosswise; 2 celery stalks, chopped; 2 bay leaves; 1 lb. small red potatoes, scrubbed, quartered; 4 cups no-salt-added clam juice; Kosher salt, freshly ground pepper; 1 lb. hot-smoked trout, skin removed, flesh broken into small pieces; 1 cup buttermilk, room temperature; ½ cup heavy cream, room temperature; Trout roe (for serving; optional)