Baked Halibut with Tomato Basil

I picked up halibut on a whim one Saturday because it looked so pristine at the market, then panicked realizing I had no real plan. A quick rummage through the fridge turned up cherry tomatoes and basil, and within half an hour I had something that tasted like I'd been planning it all week. That spontaneous dinner became one of my most-requested dishes.

The first time I made this for friends, someone asked if I'd trained in a restaurant kitchen. I laughed because I'd literally been in pajama pants under my apron. The combination of flaky white fish and that punchy, acidic relish just has a way of making any Tuesday feel a little fancy.

Ingredients

• Halibut fillets: Look for fillets that are firm, translucent, and smell like clean ocean air, not fishy. Thicker fillets stay moist better, so aim for at least an inch if possible.
• Olive oil for the fish: This helps the seasoning stick and prevents the delicate flesh from drying out in the oven.
• Lemon slices: They infuse subtle brightness as the fish bakes and look beautiful on the plate, plus they keep the top from overcooking.
• Cherry tomatoes: Quartering them releases just enough juice to make the relish saucy without being wet. I prefer the sweeter varieties like Sweet 100s.
• Fresh basil: Tear or chop it right before mixing so it stays vibrant green and fragrant, the oils fade fast once cut.
• Red onion: A small dice gives a little bite without overwhelming the tomatoes. If raw onion is too sharp for you, soak the diced pieces in cold water for five minutes and drain.
• Capers: These tiny bursts of briny tang pull the whole relish together. I always chop them so you get a bit in every bite instead of one big salty surprise.
• Extra-virgin olive oil for the relish: Use something you would happily dip bread into, the flavor really shines here.
• Balsamic vinegar: Just a tablespoon adds a touch of sweetness and depth. I learned the hard way that more is not better, it can overpower the tomatoes.
• Garlic: One small clove minced fine disappears into the relish but leaves a warm, savory undertone.

Instructions

Prep the oven and the pan:

Preheat your oven to 400°F and line a baking sheet with parchment paper. This prevents sticking and makes cleanup almost too easy.

Season the halibut:

Pat the fillets completely dry with paper towels, moisture is the enemy of a good sear or even browning. Drizzle with olive oil, season both sides with salt and pepper, then lay lemon slices on top like little shields.

Bake until just done:

Slide the pan into the oven and bake for 15 to 18 minutes. The fish is ready when it turns opaque and flakes easily with a fork, it should still be slightly glossy in the center.

Make the relish:

While the fish bakes, toss quartered cherry tomatoes, chopped basil, red onion, capers, olive oil, balsamic vinegar, and minced garlic in a bowl. Season with salt and pepper, then mix gently so the tomatoes stay intact.

Plate and serve:

Transfer each fillet to a plate and spoon the relish generously over the top. Serve immediately while the fish is hot and the relish is cool and bright.

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My mom tasted this once and said it reminded her of a little seaside restaurant we used to visit when I was a kid. I'd never made the connection before, but now every time I spoon that relish over the fish, I can almost hear the waves.

Choosing the Best Fish

Halibut is ideal because it has a mild, sweet flavor and holds its shape beautifully, but it can be pricey. Cod, sea bass, or even thick tilapia fillets work just as well if you want to save a few dollars. Whatever you choose, make sure it smells fresh and the flesh bounces back when you press it lightly.

Make-Ahead and Storage

The relish actually improves if you make it a few hours ahead and let it sit in the fridge, just bring it to room temperature before serving. Leftover fish keeps for up to two days in the fridge and reheats gently in a low oven, though the texture is best fresh. I sometimes flake leftover halibut into a salad the next day with greens and the remaining relish.

Serving Suggestions and Pairings

This dish feels light and summery, so I like to serve it with roasted asparagus, a simple arugula salad, or even just crusty bread to soak up the relish. A crisp white wine like Sauvignon Blanc or Pinot Grigio cuts through the richness of the fish and echoes the bright acidity of the tomatoes.

• For a heartier meal, serve it over a bed of orzo or couscous tossed with lemon and olive oil.
• If you want more vegetables, roasted zucchini or sautéed spinach with garlic are perfect alongside.
• Leftovers make an incredible cold lunch the next day, especially with a squeeze of fresh lemon.

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There is something deeply satisfying about a dish this simple turning out this good every single time. I hope it becomes a go-to in your kitchen the way it has in mine.

Recipe FAQs

→ What is the best way to cook halibut for this dish?

Baking halibut in the oven at 400°F allows the fillets to cook evenly while staying tender and flaky.

→ Can I prepare the tomato-basil relish ahead of time?

Yes, the relish can be made an hour in advance to allow flavors to meld, but it's best served fresh.

→ What can I substitute if halibut is unavailable?

Firm white fish like cod or sea bass work well as alternatives with similar cooking times.

→ How does the lemon enhance the dish?

Lemon slices add bright citrus notes and help keep the fish moist during baking.

→ Is this dish suitable for gluten-free diets?

Yes, all ingredients are naturally gluten-free, but double-check caper and vinegar labels for potential traces.