- 2 Tbsp. unsalted butter, divided
- 1 large onion, finely chopped
- 1 celery stalk, finely chopped
- 1 Tbsp. Old Bay seasoning
- 1 tsp. freshly ground black pepper, plus more
- 1 Tbsp. dry sherry or mirin
- 2½ cups clam juice, divided
- 2 cups fish or seafood stock or broth
- 1 lb. potatoes (any kind), peeled,cut into ½” pieces
- 1¼ lb. mixed white fish (such as swordfish and/or sea bass) and shellfish (such as peeled, deveined shrimp), cut into ½” pieces
- 8 oz. cooked lobster meat, cut into cubes (optional)
- 1 Tbsp. all-purpose flour
- ½ cup half-and-half
- Melt 1 Tbsp. butter in a large heavy pot over medium heat. Cook onion and celery, stirring often, until translucent, about 5 minutes. Mix in Old Bay and 1 tsp. pepper; cook, stirring, 30 seconds. Add sherry; cook, stirring occasionally, until alcohol has cooked off, about 1 minute. Add ½ cup clam juice; bring to a simmer. Cook, stirring occasionally, until vegetables are very soft, about 5 minutes. Add stock and remaining 2 cups clam juice and bring to a boil. Add potatoes and simmer, uncovered, adjusting heat as needed, until just tender, about 5 minutes. Add fish and shellfish and cook, stirring gently, just until mixture returns to a simmer, about 2 minutes. Remove from heat and stir in lobster meat if using.
- While the potatoes are simmering, melt remaining 1 Tbsp. butter in a small saucepan over medium heat. Whisk in flour and cook, whisking constantly, until light blond in color, about 1 minute. Whisk in half-and-half and 1 cup chowder broth (skimmed off the top) and bring to a simmer, whisking constantly. Cook, still whisking, until thickened and creamy.
- Stir half-and-half mixture into chowder ; return to medium heat. Bring to a simmer, stirring gently. Remove from heat; season with salt and more pepper. Ladle into bowls and serve with oyster crackers.