Baked Halibut With Fennel Walnut

The smell of toasted walnuts and lemon zest hit me before I even opened the oven. I was testing this halibut recipe on a drizzly Thursday, halfway convinced it wouldn't live up to the hype I'd built in my head. But when I pulled that baking dish out and saw the golden crust catching the kitchen light, I knew I'd stumbled onto something special. The fennel had softened into sweet, aromatic ribbons beneath perfectly flaky fish. It tasted like the kind of meal you'd order at a bistro with white tablecloths, except I made it in sweatpants.

I made this for my sister when she visited last spring, mostly because I wanted to show off a little. She's the kind of cook who makes everything from scratch, so I needed something that wouldn't embarrass me. When she took her first bite and paused mid-chew to ask for the recipe, I felt ridiculously proud. We ended up eating straight from the baking dish at the counter, too hungry to bother with plating. She still texts me photos whenever she makes it now.

Ingredients

• Halibut fillets: The star here, mild and meaty enough to hold up to baking without drying out, though I've had equal success with cod when halibut prices spike.
• Fennel bulb: Slicing it thin is key so it softens completely in the oven and releases that gentle anise sweetness that plays beautifully with lemon.
• Lemon: Both zest and juice do double duty, brightening the fish and the topping, so don't skip zesting before you juice.
• Fresh breadcrumbs: I tear up day-old rustic bread and pulse it briefly, the irregular texture crisps up better than store-bought.
• Walnuts: Chopped finely so they distribute evenly and toast quickly, adding earthy richness that balances the brightness.
• Garlic: Just one clove, minced fine and toasted until fragrant, never let it go dark or it turns bitter.
• Fresh parsley: Stirred in at the end to keep its color vibrant and its flavor bright against all that butter and oil.
• Olive oil: I use a fruity one for drizzling and a more neutral one for toasting the breadcrumbs, but honestly any good olive oil works.

Instructions

Prep the oven and dish:

Preheat to 200°C and rub a baking dish with a little olive oil so nothing sticks. Make sure the dish is big enough that the fillets sit flat without crowding.

Build the fennel base:

Scatter those thin fennel slices across the bottom, drizzle with oil and half the lemon juice, then season lightly. This layer will steam and caramelize under the fish, becoming almost jammy.

Nestle the fish:

Lay the halibut fillets on top of the fennel, drizzle with the remaining oil and lemon juice, and season again with salt, pepper, and half the lemon zest. Don't be shy with the seasoning, fish needs it.

Toast the pangrattato:

Warm olive oil in a skillet over medium heat, add garlic and breadcrumbs, and stir constantly until golden and crisp, about 3 minutes. Toss in the walnuts for another minute, then pull it off the heat and stir in parsley and the rest of the lemon zest.

Top and bake:

Spoon the walnut mixture over each fillet, pressing gently so it sticks. Slide the dish into the oven and bake for 12 to 15 minutes, until the fish flakes easily and the topping is deeply golden.

Serve hot:

Pull it out, let it rest for just a minute, then serve straight from the dish or plate it up with a scattering of fennel fronds. The contrast between the crunchy top and tender fish is everything.

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There was a Sunday last winter when I made this for myself after a long week and realized halfway through eating that I hadn't checked my phone once. The combination of crunch, citrus, and that sweet fennel underneath just pulled me completely into the moment. It's become my go-to meal when I need to feel like I'm taking care of myself, not just feeding myself. Food like this reminds me why I love cooking in the first place.

Choosing Your Fish

Halibut is ideal because it's firm and forgiving, but I've swapped in cod, haddock, and even sea bass depending on what looked good at the market. The key is choosing fillets that are similar in thickness so they cook evenly. If you end up with thinner pieces, check them a few minutes early to avoid overcooking. I learned this the hard way when I baked delicate sole and ended up with expensive fish jerky.

What to Serve Alongside

This dish is rich enough that it doesn't need much company. I usually throw together a simple arugula salad with a sharp vinaigrette or steam some baby potatoes and toss them in butter and dill. On nights when I'm feeling fancy, I'll roast asparagus or green beans alongside the fish in the same oven. A crisp white wine like Sauvignon Blanc or Vermentino cuts through the richness beautifully and makes the whole meal feel occasion-worthy.

Making It Your Own

Once you've made this a few times, it's easy to riff on. I've swapped the walnuts for almonds or hazelnuts, added a pinch of red pepper flakes to the pangrattato for warmth, and even stirred in orange zest when I didn't have enough lemon. The fennel can be replaced with thinly sliced leeks or shallots if you're not a fan of anise flavors. Just keep the basic structure, fish on a flavorful base with a crunchy topping, and you'll end up with something delicious every time.

• Try pistachios in place of walnuts for a sweeter, greener flavor.
• Add a handful of cherry tomatoes to the fennel for bursts of acidity.
• Finish with a drizzle of good balsamic if you want a touch of sweetness.

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This is the kind of recipe that makes weeknight cooking feel like less of a chore and more of a treat. I hope it becomes one of those dishes you reach for when you want something special without the stress.

Recipe Questions

→ Can I substitute another fish for halibut?

Yes, cod, haddock, or sea bass work beautifully as alternatives. Choose firm white fish fillets of similar thickness for even cooking.

→ How do I know when the halibut is fully cooked?

The fish should be opaque throughout and flake easily when tested with a fork. Internal temperature should reach 63°C (145°F).

→ Can I make the pangrattato ahead of time?

Yes, prepare the toasted breadcrumb mixture up to 2 days in advance and store in an airtight container at room temperature.

→ What side dishes pair well with this halibut?

Steamed baby potatoes, roasted asparagus, or a crisp green salad complement the flavors perfectly without overwhelming the delicate fish.

→ Is this dish suitable for gluten-free diets?

Substitute the breadcrumbs with gluten-free alternatives or crushed gluten-free crackers to make this dish celiac-friendly.

→ What wine pairs best with this halibut dish?

A chilled Sauvignon Blanc or Vermentino highlights the citrus and fennel notes while complementing the richness of the walnuts.