Baked Sardines with Potatoes, Onions, and Lemon

Why You’ll Love This Recipe

• Classic Spanish comfort: rustic layers of potato and onion under juicy, fresh sardines.
• Weeknight-easy: one pan, minimal prep, and done in under an hour.
• Bright, clean flavors: lemon, garlic, and parsley keep it fresh and vibrant.
• Balanced and satisfying: crisp-edged veg with rich, flaky fish.

Grocery List

• Produce: Yukon Gold potatoes, yellow onion, garlic, lemons, flat-leaf parsley
• Dairy: None
• Pantry: Fresh whole sardines (from fish counter), extra-virgin olive oil, dry white wine or fish stock (optional), smoked paprika (optional), kosher salt, black pepper

Full Ingredients

Vegetable Base

• 1.5 lb (680 g) Yukon Gold potatoes, scrubbed and sliced 1/4 in (6 mm) thick
• 1 large yellow onion (about 300 g), thinly sliced
• 3 tbsp extra-virgin olive oil
• 1/4 cup (60 ml) dry white wine or fish stock (optional but recommended)
• 1 tsp kosher salt
• 1/2 tsp freshly ground black pepper
• 1/2 tsp smoked Spanish paprika (pimentón dulce), optional

Sardines and Finish

• 12 small-to-medium fresh sardines (about 1.5 lb/680 g), scaled and gutted
• 2 tbsp extra-virgin olive oil
• 4 garlic cloves, thinly sliced
• 1 large lemon: 1 tsp finely grated zest + 2 tbsp juice, plus 4 thin slices
• 1/4 cup (10 g) flat-leaf parsley, finely chopped, divided
• 1/2 tsp kosher salt
• 1/4 tsp freshly ground black pepper
• Flaky sea salt and extra olive oil, for serving

Step-by-Step Instructions

Step 1: Heat the oven and prepare the pan

Preheat the oven to 425°F (220°C) with a rack in the middle. Lightly oil a 9×13-inch (23×33 cm) baking dish or a large rimmed sheet pan. This high heat ensures the potatoes crisp and the sardines bake quickly without drying out.

Step 2: Slice and season the vegetables

Slice potatoes into even 1/4-inch (6 mm) rounds and the onion into thin half-moons. In a large bowl, toss the potatoes and onion with 3 tbsp olive oil, 1 tsp kosher salt, 1/2 tsp black pepper, and the smoked paprika if using. Spread evenly in the pan. Pour the wine or stock around the edges to create a little steam that helps the onions soften while the potatoes brown.

Step 3: Pre-roast the potato and onion layer

Roast for 20 minutes, stirring once halfway through. You’re looking for the potatoes to be just tender in the center and starting to color at the edges. If your slices are thicker, add 3–5 more minutes.

Step 4: Season the sardines

While the vegetables roast, pat the sardines very dry. In a bowl, combine 2 tbsp olive oil, the sliced garlic, lemon zest, lemon juice, half the chopped parsley, 1/2 tsp kosher salt, and 1/4 tsp pepper. Add the sardines and gently turn to coat. Let sit 10 minutes to absorb the flavors.

Step 5: Assemble and bake

Remove the pan from the oven. Spread the vegetables back into an even layer. Arrange the sardines on top, skin-side up, in a single layer. Tuck in the lemon slices and spoon any remaining marinade over everything. Return to the oven and bake 8–12 minutes, until the sardines flake easily with a fork and reach about 140°F (60°C) in the thickest part. The potato edges should be crisp and golden.

Step 6: Finish and serve

Scatter the remaining parsley over the top, drizzle with a little more olive oil, and add a final squeeze of lemon if you like. Let rest 2 minutes to settle the juices, then serve straight from the pan. Tip: If you want extra color, broil for 1–2 minutes, watching closely.

Pro Tips

• Choose ultra-fresh sardines: bright, clear eyes and a clean ocean scent. Ask the fishmonger to scale and gut them.
• Even slices, even cooking: keep potatoes at 1/4 inch (6 mm). A mandoline makes quick work.
• Dry fish, crispy skin: pat sardines very dry before marinating so the skin blisters rather than steams.
• Doneness cues: sardines are ready when they flake easily and the skin is lightly blistered; don’t overbake.
• One-pan advantage: use a metal sheet pan for the best crisp edges; ceramic dishes will be slightly softer.

Variations

• Tomato and Olive: Add 1 cup halved cherry tomatoes and 1/3 cup pitted green olives to the vegetables for a briny, juicy twist.
• Herby Breadcrumb Top: Mix 1/2 cup fresh breadcrumbs with 1 tbsp olive oil, 1 tbsp parsley, and a pinch of paprika; sprinkle over the sardines before the final bake.
• Fennel and Orange: Swap onion for 1 small bulb fennel (thinly sliced) and finish with a few strips of orange zest alongside the lemon.

Storage & Make-Ahead

Best enjoyed fresh. Refrigerate leftovers in an airtight container for up to 2 days; reheat at 350°F (175°C) for 10–12 minutes, then broil briefly to re-crisp. You can pre-roast the potato-onion layer up to 24 hours ahead; cool, cover, and refrigerate, then rewarm 5 minutes before adding sardines. Marinate the sardines no more than 15 minutes before baking. Freezing cooked sardines is not recommended; raw cleaned sardines can be frozen up to 3 months.

Nutrition (per serving)

Approximate: 680 calories; 37 g fat; 8 g saturated fat; 38 g carbohydrates; 6 g fiber; 4 g sugars; 46 g protein. Sodium varies based on salt used.