This lemon-dill butter fish is our cosy winter special, and it is one of the easiest ways to make air fryer fish that tastes restaurant-worthy at home. A thick white fish fillet is coated in a zesty paste of melted butter, Dijon mustard, citrus and our house dill rub, then air-fried until golden on top and juicy and flaky inside. Served with tender-crisp roasted asparagus and a wedge of lemon, it is a light, fresh-tasting dinner for one that is ready in about 15 minutes.

- Serves: 1
- Prep time: 5 minutes (plus 2 minutes for the dill rub, made once)
- Cook time: about 15 minutes
- Protein: around 35g per serving
- Diet: gluten-free and low-carb (without the optional crumb coating)
Ingredients
A. House Dill Rub (Makes Enough for 15–20 Servings)
- 2 tbsp dried dill
- 1 tbsp dried lemon peel powder (or 2 tsp finely grated fresh lemon zest if making it fresh)
- 1 tbsp garlic powder
- 1 tsp ground white pepper
- 1 tsp smoked paprika
- 1 tsp sea salt
Mix everything together and store in an airtight jar. It keeps for up to 3 months and is also lovely on chicken, potatoes and roasted vegetables.
B. For the Fish
- 1 thick white fish fillet, about 180g: sea bass, cod, haddock or halibut all work well (in the Gulf, hamour is a popular choice)
- 2½ tbsp butter, melted
- 1 tsp Dijon mustard
- 1 tbsp fresh lime juice
- 1 tsp fresh lemon zest
- 2 tsp house dill rub
- Fresh dill sprigs, to garnish
- Optional, for an extra-crispy crust: 3 tbsp panko breadcrumbs
C. For the Side
- 8 asparagus spears, woody ends snapped off
- 1 tbsp butter, melted
- Salt and freshly ground black pepper, to taste
- 1 lemon wedge, to serve
Method
Step 1: Prepare the Fish
Pat the fish completely dry with kitchen paper; this is the key to a golden finish. In a small bowl, mix the melted butter, Dijon mustard, lime juice, lemon zest and dill rub into a thick paste. Spread it evenly over all sides of the fish. For the crispy crust shown in the photo, press the panko breadcrumbs onto the top of the coated fillet.
Step 2: Air Fry the Fish
Place the fillet in the air fryer basket (a piece of air fryer parchment helps it lift out cleanly) and cook at 200°C (400°F) for 9–10 minutes. Do not flip it. The fish is ready when it is opaque and flakes easily with a fork; if you have a food thermometer, it should read 63°C (145°F) in the thickest part. Thinner fillets will need a couple of minutes less.
Step 3: Roast the Asparagus
Toss the asparagus with the melted butter, salt and pepper. Air fry at 190°C (375°F) for 4–5 minutes until bright green and tender-crisp. If your air fryer is large enough, you can add the asparagus to the basket for the last 5 minutes of the fish’s cooking time.
Step 4: Serve
Place the fish on a warm plate, wooden board or, for a special touch, a rustic serving boat. Arrange the asparagus alongside, add a lemon wedge and finish with fresh dill. Serve straight away.
Why You Will Love This Air Fryer Fish
- Crispy outside, juicy inside: The butter and mustard coating seals the surface and helps keep the fillet moist.
- No deep-frying: All the golden colour comes from the air fryer, with no oil bath.
- Fresh and aromatic: Dill, lemon and lime keep the flavour bright, and the citrus helps balance any strong fishy taste.
- High in protein, low in carbs: A great choice for a light but satisfying dinner.
- Make-ahead rub: Mix the dill rub once and you have dinner seasoning ready for weeks.
Nutrition (Approximate, Per Serving)
- Calories: around 550 kcal as written (around 380 kcal if you halve the butter)
- Protein: around 35g
- Fat: around 42g, mostly from the butter
- Carbohydrates: around 6g (around 16g with the panko crust)
This is a rich, buttery air fryer fish recipe. For a lighter version, use 1 tbsp butter in the fish paste and 1 tsp olive oil for the asparagus; the fish will still be juicy thanks to the mustard and citrus. Figures are estimates and will vary with your fish and portion size.
Make It Your Own
- Choose your fish: Sea bass for an extra-soft, delicate texture; cod or haddock for big, flaky pieces; salmon for a richer option (add 2 minutes).
- Choose your side: Roasted asparagus or buttered green beans; tenderstem broccoli works beautifully too.
- Make it a bigger meal: Add a few crispy air fryer potatoes or a small portion of herby rice.
- More air fryer ideas: Try our Juicy Air Fryer Chicken Tikka with Grilled Veggies.
Tips for Perfect Air Fryer Fish
- Dry fish = golden fish: Any moisture on the surface will steam the fillet instead of crisping it.
- Choose thick fillets: Thicker cuts (around 2.5cm / 1 inch) stay juicy; thin fillets cook very quickly.
- Frozen fish: Thaw it fully in the fridge overnight and pat it very dry before coating.
- About dill: Dill is a classic partner for fish in Scandinavian and Eastern European cooking, and its fresh, grassy flavour works wonderfully with lemon and butter.
Allergy Information
Contains fish, dairy (butter) and mustard. The optional panko crust contains gluten (wheat); use gluten-free breadcrumbs if needed. Eat air fryer fish straight away, or refrigerate leftovers within an hour and eat within 1 day.