Whole Sea Bass ​With Lime And Dill Butter

I wasn’t planning to cook whole fish on a random Thursday night. But I walked past my local fishmonger, saw these glistening sea bass in the display, and thought—why not? It felt ambitious, a bit “cheffy”, but honestly? This turned out to be one of the simplest, most satisfying things I’ve cooked all month.

The first time I tried this, I forgot to seal the foil packets tightly. Result? Half the butter pooled into the oven tray, and the fish came out a little sad and dry. The second time, I got it right—and wow. That lime-dill butter soaked into every bite, and the creamy sauce on the side took it from “weeknight dinner” to “dinner party showstopper”.

If you’ve never cooked a whole fish before, don’t panic. This one’s incredibly forgiving—and I’ll walk you through every step.

The Secret Behind This Bake

What makes this special is the foil wrap. It’s basically a spa treatment for the sea bass—steams it gently while locking in all that buttery citrus flavour. And unlike many fish dishes, this one isn’t just about the main event. The lime and dill butter gets into all the nooks of the fish, while the creamy sauce on the side balances it out with a tangy, slightly sweet richness.

Bonus: it’s just as good on the barbecue, which makes it a brilliant summer option too.

INGREDIENTS + WHY THEY MATTER

• Whole sea bass (700g each) – Mild, sweet, and meaty. I’ve used trout as a swap, but sea bass wins for texture and presentation.
• Butter – Softened so it melts easily into the slashes. Once I used fridge-cold butter, and it didn’t spread well—left clumps.
• Lime zest and juice – Brightens up the whole dish. Keep the squeezed halves—they add loads of flavour when tucked inside the fish.
• Dill – The classic pairing. If you don’t like dill, flat-leaf parsley works, but it won’t have quite the same summery kick.
• Picanté peppers – These add a gentle sweetness and colour. I tried roasted red peppers once—okay in a pinch, but less punchy.
• Crème fraîche – Forms the base of the sauce. Double cream makes it too heavy; yoghurt too sharp.
• Dijon mustard – A tiny hit of heat that rounds out the sauce.
• Caster sugar – Sounds odd, but it balances the lime perfectly. Don’t skip it.

Ingredient Swaps That Hold Up

• Fish substitute: Whole trout or snapper also work. Just adjust cooking time slightly based on size.
• Dairy-free: Use a plant-based butter for the fish and coconut cream or oat crème fraîche for the sauce. Slightly different flavour, but still tasty.
• Peppers: If picanté peppers are tricky to find, use finely diced peppadews or mild jarred red peppers.
• Herbs: No dill? Try tarragon or parsley. Dill is best, but others will still work in a pinch.

MISTAKES I’VE MADE (AND HOW TO AVOID THEM)

What Went Wrong	Why It Happens	How to Fix It
Butter leaked everywhere	Foil not sealed tightly enough	Crimp the foil edges properly like a pasty
Fish dried out	Overcooked or wrapped loosely	Stick to the 20-minute mark and turn halfway
Skin stuck to tray	Placed directly on a baking sheet	Cook on foil or oven shelf to prevent sticking

HOW TO MAKE MARY BERRY’S WHOLE SEA BASS WITH LIME AND DILL BUTTER

1. Preheat the oven to 200°C/180°C fan. Grease two sheets of foil with a bit of butter.
2. Make the lime butter: Mix softened butter with half the lime zest and juice, chopped dill, and peppers. Season well.
3. Prepare the fish: Make 3 diagonal cuts on each side of the sea bass. Rub the lime butter into the cuts and all over. Stuff the cavity with dill stalks and used lime halves.
4. Wrap the fish: Place each on foil, wrap tightly, and seal the edges. Bake or barbecue for 20 minutes, flipping halfway.
5. Make the sauce: Stir crème fraîche, mustard, sugar, remaining lime zest and juice, and leftover dill and peppers in a bowl. Taste and adjust seasoning.
6. Serve: Carefully unwrap the fish, sprinkle with more dill, and serve with the sauce. Lift off fillets or let guests flake their own at the table.

TIPS FROM MY KITCHEN

• I grease the foil generously to help prevent sticking—especially if I’m grilling it.
• If I want crispy skin, I unwrap the fish for the last 5 minutes and whack it under the grill.
• For easier serving, I run a knife along the backbone to lift the fillet off cleanly.
• I keep a teaspoon of sugar handy when making the sauce—it balances the lime if it’s too sharp.

STORAGE + SERVING

• Fridge: Once cool, remove the fillets from the bone and store in an airtight container for up to 2 days.
• Freezer: Best eaten fresh, but you can freeze the cooked, flaked fish for up to a month. Use it for fishcakes or a fancy sandwich.
• Reheating: Gently warm in a pan on low heat—or serve cold with a green salad and new potatoes.

FREQUENTLY ASKED QUESTIONS

Q: Can I cook this in advance?
A: You can prep the fish and wrap it in foil a few hours ahead. Keep it in the fridge, then bake just before serving.

Q: Can I use fillets instead of whole fish?
A: You can, but you’ll lose the benefit of steaming in the cavity with the lime and dill. Whole fish gives better flavour.

Q: Is this dish good for the barbecue?
A: Yes! It cooks beautifully over hot coals. Just flip it once halfway through and keep the foil sealed.

Q: What if I don’t like dill?
A: Try parsley or a little tarragon. But dill really does make the citrus pop here.

Q: Can I use lemon instead of lime?
A: You can—but lime has a slightly sweeter, more floral edge that pairs better with the butter and peppers.

Try More Mary Berry Recipes:

• Mary Berry Fish Curry With Coconut Milk
• Mary Berry Fish Pie With Crushed Potatoes
• ​Mary Berry Smoked Salmon And Haddock Kedgeree​
• Mary Berry Fish Pie