How to Fillet a Whole Fish (Like a Pro)

Filleting a fish sounds intimidating, but once you get the hang of it, it's actually quite satisfying. It's also way more economical than buying pre-cut fillets and you get full control over quality, cut size, and what happens to the bones. Here's how to break down a whole fish at home, step by step.

Why Buy Whole Fish in the First Place?

Before we get into the technique, let's talk about why it's worth it. Buying whole fish is almost always cheaper per kilogram than buying pre-cut fillets sometimes significantly so. But more importantly, whole fish tells you far more about freshness than fillets do.

A pre-cut fillet sitting in a supermarket display has already had its most visible freshness indicators removed. A whole fish hides nothing: you can see the eyes, check the gills, smell it, and feel the flesh. That transparency is valuable.

There's also the matter of yield. When you fillet at home, you're in control of every cut no wasted scraps, no thin fillet edges trimmed away for presentation. And the leftover carcass is the start of a beautiful fish stock.

How to Choose a Fresh Whole Fish

Before you even think about the knife, buy well. Here's what to look for:

• Eyes: Clear and bright, slightly protruding. Cloudy or sunken eyes mean it's been sitting around too long.
• Gills: Lift them and check the color. Bright red is good. Brown or grey means it's past its best.
• Smell: A fresh fish smells like the sea clean and faintly briny. A strong fishy smell is a bad sign.
• Flesh: Press gently on the side of the fish. It should spring back. If it leaves an indentation, the fish is soft and old.

Step 1: Dry it off

Start with a dry fish and a dry board. Pat yours down with paper towels it makes a huge difference. Better grip, safer cuts, no slipping around.

Step 2: Remove the Head

With your knife just behind the gills, angle the blade slightly toward the head and make a clean downward cut. You should hit the collarbone give it a small wiggle and slice through. Do the same on the other side of the neck to fully detach the head.

Tip: Keep the head for stock, or broil it with flaky salt there's loads of flavour in the collagen around the cheeks and jaw.

Step 3: First Fillet Glide Down the Top

Place the fish belly-down, spine facing up. Run your knife along the top line from where the head used to be, all the way to the tail. Let the blade follow the backbone. You're just opening it up don't cut through yet.

Once the top line is open, work the knife deeper, using long, gentle but firm strokes to lift the fillet away from the bones. Keep the blade flat and close to the spine the cleaner your angle, the less meat you leave behind.

Step 4: Second Fillet Go Under the Spine

Without flipping the fish, slide your knife underneath the spine from the tail end, and gently separate the second fillet. Once you've cut through to the belly line, you can lift the entire spine off in one go super, super satisfying stuff.

Step 5: Clean Up

Trim off any scrappy bits and check for pin bones by running your fingers along the flesh. Use fish tweezers or pliers to pull them out. You'll end up with two tidy fillets, ready for portioning.

Step 6: Portioning

Make long, firm strokes along the fillets to cut your desired sizes and you're done! Sear, bake, poach you've got fillets ready to go.

Knife Talk

You don't need anything fancy just a sharp, flexible filleting knife. The flex helps you glide over bones without hacking through them. If your cuts feel jagged or messy, you probably need to sharpen the blade.

Don't Toss the Bones

Always keep the head and spine for stock. Throw them in a pot with water, mirepoix, and maybe a bay leaf or two. Simmer gently for 30–40 minutes and strain you've now got liquid gold for risotto, soups, or sauces. Essentially, fish stock.

Vacuum Seal = Freshness

Once portioned, vacuum seal the fillets either whole or pre-cut and store them in the freezer. If you're cooking them within a couple of days, they go in the fridge still sealed. No mess, no smell, no drying out.

That's it. No flipping, no stress. Just a simple way to turn a whole fish into two clean fillets and make use of every part while you're at it.