Haddock Recipe

1. Prep fish

Pat haddock fillets dry with paper towels. Season both sides lightly with 1/2 tsp of the fine salt and 1/4 tsp black pepper. Keep chilled until ready to batter.

2. Make batter

In a medium bowl whisk together all-purpose flour, cornstarch and baking powder. Stir in the remaining 1/2 tsp salt and 1/4 tsp pepper. In a separate small bowl beat the egg, then whisk egg into the dry mix. Gradually pour in cold sparkling water and whisk just until combined; batter should be slightly thick but still pourable and have bubbles — do not overmix.

3. Heat oil

Pour neutral frying oil into a heavy skillet or pot to a depth of about 1 inch. Heat over medium-high until oil registers 350°F (175°C) or a piece of batter sizzles and browns within 30–40 seconds.

4. Fry fish

Dredge each seasoned haddock briefly in a little flour (optional — helps batter adhere), then dip into the batter, letting excess drip off. Carefully lower into hot oil. Fry 2–3 pieces at a time (do not crowd) for 3–4 minutes per side, turning once, until golden brown and fish registers 145°F (63°C) and flakes easily. Use a slotted spatula to transfer to a wire rack set over a sheet pan; keep warm in a 200°F oven while frying remaining fillets.

5. Finish

When all fillets are cooked, briefly blot any excess oil with paper towel and squeeze a little lemon over fish if desired before assembling.

6. Combine rice vinegar, water, sugar, salt and mustard seeds in a small saucepan. Bring to a gentle simmer and stir until sugar dissolves. Remove from heat and let cool for 3 minutes.

7. Place julienned carrots, sliced cucumber and red onion in a heatproof bowl or jar. Pour warm pickling liquid over vegetables to cover. Let cool to room temperature, then refrigerate at least 30 minutes (preferably 1 hour) before serving. Will keep refrigerated up to 4 days.

8. In a small bowl combine mayonnaise, chopped capers, lemon zest, lemon juice, minced garlic, Dijon mustard and olive oil. Whisk until smooth. Season with salt and pepper to taste. Chill for at least 15 minutes to allow flavors to meld.

9. Toast buns: heat a skillet over medium, add butter and toast cut sides of brioche buns until golden, about 1–2 minutes. Keep warm.

10. Assemble sandwiches: spread 1 to 1 1/2 tablespoons lemon-caper aioli on the bottom half of each brioche bun. Place 2 bibb lettuce leaves on aioli, top with a crispy haddock fillet, then a generous spoonful of pickled vegetables (about 2–3 tablespoons). Add an additional drizzle of aioli on the top bun if desired. Garnish with a sprinkle of chopped dill or parsley and serve with lemon wedges.

11. Serve immediately while fish is hot and crispy.