Crab-Stuffed Flounder with Lemon Butter Sauce (Easy Christmas Eve Seafood Dinner)

Why you’ll love it

• Elegant but easy: simple rolled fillets that look impressive on a holiday table.
• Loaded with crab: a generous, buttery stuffing with sweet lump crabmeat in every bite.
• Light and bright: mild, flaky fish and a fresh lemon butter sauce keep it from feeling heavy.

Quick facts

Ingredients

For the crab stuffing

• 8 oz (225 g) lump crabmeat, drained and picked over for shells
• 1 tbsp (14 g) unsalted butter
• 1/3 cup (50 g) finely diced yellow onion
• 1/3 cup (40 g) finely diced celery
• 1 garlic clove, minced
• 1/4 cup (55 g) mayonnaise
• 1 large egg
• 1 tsp Dijon mustard
• 1 tsp Old Bay seasoning
• 1 tsp finely grated lemon zest
• 1 tbsp chopped fresh parsley
• 1/2 cup (40 g) crushed buttery round crackers, such as Ritz (about 12 crackers)

For the flounder

• 8 thin skinless flounder fillets (3 to 4 oz / 85 to 115 g each, about 1 3/4 lb / 800 g total)
• 1/2 tsp kosher salt
• 1/4 tsp black pepper
• 2 tbsp (28 g) unsalted butter, melted
• 1/4 tsp paprika
• 1/4 cup (60 ml) dry white wine or low-sodium chicken broth

For the lemon butter sauce

• 4 tbsp (56 g) unsalted butter
• 2 tbsp fresh lemon juice
• 1 tbsp chopped fresh parsley
• Lemon wedges, for serving

Step-by-step method

1. Heat the oven. Heat the oven to 400°F (200°C) and generously butter a 9 x 13-inch (23 x 33 cm) baking dish.

2. Cook the aromatics. Melt 1 tablespoon butter in a small skillet over medium heat. Add the onion and celery and cook 4 to 5 minutes, stirring, until soft. Add the garlic and cook 30 seconds, until fragrant. Let it cool for 5 minutes.

3. Make the stuffing. In a medium bowl, whisk the mayonnaise, egg, Dijon, Old Bay, lemon zest and parsley. Stir in the cooled vegetables and the crushed crackers. Add the crabmeat and fold it in very gently so the lumps stay whole.

4. Season and fill the fillets. Pat the flounder dry with paper towels and season both sides with the salt and pepper. Lay the fillets on a cutting board with the darker side (where the skin was) facing up. Place about 1/3 cup of stuffing on the wide end of each fillet, roll it up snugly toward the thin end and set it seam side down in the baking dish.

5. Brush and add the wine. Stir the paprika into the 2 tablespoons melted butter and brush it over the rolls. Pour the wine or broth into the bottom of the dish, around the fish.

6. Bake. Bake 20 to 25 minutes, until the fish is opaque and flakes easily with a fork and the stuffing is hot in the center.

7. Make the sauce and serve. While the fish rests for 2 minutes, melt 4 tablespoons butter in a small saucepan over medium heat. Carefully tilt the baking dish and add about 1/4 cup of the pan juices and the lemon juice to the butter. Simmer 1 minute, then stir in the parsley. Spoon the sauce over the stuffed flounder and serve with lemon wedges.

How to know it is done

The flounder is done when it has turned from translucent to opaque white all the way through and flakes easily when you press it with a fork. The fish should reach 145°F (63°C) and the center of the stuffing, which contains egg, should reach 165°F (74°C) on an instant-read thermometer. The tops of the rolls will look lightly golden and the juices in the dish will be bubbling gently.

Tips for the best result

• Choose thin fillets about 1/4 inch (6 mm) thick; they roll easily and cook at the same time as the stuffing.
• Pick through the crab carefully with your fingers to remove any bits of shell, but do not break up the lumps.
• Pat the fish very dry so the butter sticks and the sauce is not watery.
• If a fillet tears, simply overlap the pieces and roll; once baked no one will notice.
• Do not overbake. Flounder is delicate and goes from tender to dry in just a few minutes.

Variations and substitutions

• Other fish: use sole, tilapia or thin cod fillets with the same method.
• Shrimp and crab stuffing: replace half of the crab with 4 oz (115 g) chopped raw shrimp.
• Budget version: use claw crabmeat, or half crab and half imitation crab.
• Thick fillets: if your fillets are too thick to roll, make sandwiches: spread the stuffing between two fillets and bake 20 to 25 minutes.
• Gluten-free: use gluten-free crackers and check that the Old Bay and mayonnaise are gluten-free.
• Without wine: use chicken broth or seafood stock plus 1 teaspoon lemon juice.

Make ahead

Make the crab stuffing up to 1 day ahead and refrigerate it covered. You can roll the fillets and arrange them in the buttered baking dish up to 4 hours ahead; cover tightly and refrigerate. When ready, brush with the paprika butter, add the wine and bake, adding 3 to 5 minutes to the baking time because the dish is cold. Make the lemon butter sauce just before serving.

Storage and reheating

Refrigerate leftovers in an airtight container for up to 2 days. Reheat in a covered baking dish in a 325°F (165°C) oven for 10 to 12 minutes, until hot, with a splash of broth or a little butter so the fish does not dry out. The microwave works on medium power in 30-second bursts. Freezing is not recommended because the delicate fish becomes watery.