Serves a hearty 8
1 cup each: milk and water
1 1/2 pounds potatoes (I used Yukon Golds), peeled and, depending on size, halved or quartered lengthwise and sliced 1/4-inch thick
1 cup each: dry white wine and water
5 to 7 large dill sprigs, plus extra leaves and/or minced for garnish
1 pound sea scallops, halved crosswise
1 pound firm white-fleshed cod or halibut
1 pound boneless, skinless salmon
2 pounds (31 to 40 count) cooked shrimp, tails removed
8 ounces pasteurized lump crabmeat
4 tablespoons butter
1 medium onion, cut into small dice (about 1 cup)
1 pound domestic white or baby bella mushrooms, sliced
1/4 cup dry sherry
1/4 cup flour
1 quart light cream
1/4 teaspoon ground nutmeg
1/2 teaspoon white pepper
Bring milk and water, potatoes, and a generous sprinkling of salt to boil in a large, wide pot over medium high heat. Reduce heat to medium-low and simmer partially covered, until just tender, 5 to 7 minutes. Drain, transferring potatoes to a large bowl and reserving milk mixture. Rinse out pot and return to stove.
Add wine, water and dill to pot over low heat. Squeeze in lemon juice, tossing in the shell. Add scallops; cover and gently poach until just cooked, about 5 minutes. Transfer with a slotted spoon to bowl with potatoes. Add fish; cover and gently poach until just cooked, 8 to 10 minutes. Transfer with a slotted spoon to bowl with scallops. Add shrimp and crab to bowl as well. Strain poaching liquid and reserve. Rinse out pot and return to stove.
Add butter to pan and melt over medium heat. Add onion; sauté until tender, 3 to 4 minutes. Increase heat to medium-high; add mushrooms and sauté until their liquid has completely evaporated, 5 to 7 minutes. Add sherry; cook until evaporated, about a minute. Add flour; whisk until smooth. Whisk in cream, seasoning with nutmeg and pepper. (Can be made and left at room temperature up to 2 hours)
When ready to serve, add seafood and potatoes to pot and very slowly heat chowder, adding poaching liquid to desired thickness. Adjust seasonings. Ladle into bowls, garnishing with chopped dill.