Seared Swordfish with Burst Tomato Caper Sauce

This one-pan swordfish dinner brings the sunny flavors of the Mediterranean to your table in under 30 minutes. Thick steaks are seared until golden, then bathed in a burst cherry tomato, caper, and kalamata olive sauce that comes together right in the skillet.

A spoonful of garlic herb butter makes it glossy and rich, while fresh oregano, lemon rounds, and grated aged sheep milk cheese add brightness and depth. It's the kind of meal that feels special enough for a dinner party but simple enough for a busy weeknight.

Swordfish is a meaty, steak-like fish that stands up beautifully to high heat and bold flavors. Here, it's seared in a hot cast iron skillet with olive oil and butter, then finished with a quick sauce of cherry tomatoes, capers, and kalamata olives.

The tomatoes burst into a juicy, slightly sweet sauce, the capers add briny pops, and the olives bring a rich, savory note. A spoonful of garlic herb butter ties it all together, and a shower of fresh oregano and grated sheep milk cheese completes the dish. Serve it with lemon rounds on the side for squeezing.

Ingredients

Why this recipe works

The high heat of a cast iron skillet creates a deep, golden crust on the swordfish while keeping the interior moist and tender. Searing the fish first, then building the sauce around it, allows the fish to absorb the flavors without overcooking. The burst tomatoes release their juices, which combine with the butter and olive oil to form a naturally emulsified pan sauce.

Using a combination of olive oil and butter gives the sauce richness and depth, while the capers and olives add a briny contrast that cuts through the richness of the fish.

The garlic herb butter is stirred in at the end, off the direct heat, so its aromatics stay fresh and fragrant. The result is a balanced, restaurant-quality dish that comes together in one skillet with minimal cleanup.

Notes and substitutions

Choose swordfish steaks that are about 1 inch thick and look firm and moist, without any dark spots or strong fishy smell. If swordfish isn't available, halibut or mahi-mahi are good substitutes, though cooking times may vary. For the cheese, look for a firm aged sheep milk cheese like Manchego or Pecorino Romano—grate it fresh for the best texture and flavor.

A cast iron skillet is ideal for this recipe because it holds heat well and gives the fish a beautiful crust. If you don't have one, a heavy stainless steel or nonstick skillet will work, but adjust the heat as needed.

The garlic herb butter can be store-bought or homemade; if making your own, combine softened butter with minced garlic and chopped fresh herbs like oregano, thyme, or parsley.

• swordfish steaks: halibut, mahi-mahi, or thick white fish fillets (adjust cooking time as needed)
• aged sheep milk cheese: Parmesan or Asiago (if not avoiding cow's milk)
• garlic herb butter: mix 3 tbsp softened butter with 1 minced garlic clove and 1 tsp chopped fresh herbs (oregano, thyme, or parsley)

Equipment

• Cast iron skillet (12-inch)
• Box grater
• Chef's knife
• Cutting board
• Tongs
• Measuring spoons
• Small bowl