Seared Tuna Steak with Mustard-Parsley Sauce

This Seared Tuna Steak with Mustard-Parsley Sauce is a tender, flavor-packed fish dish perfect for seafood lovers. Lightly crusted with crushed white peppercorns and coriander seeds, then seared to perfection, this restaurant-style meal comes together with a vibrant, tangy herb sauce that enhances every bite. Ideal for a quick yet elegant dinner or a special lunch.

Why Everyone Will Love This Recipe

• Tender, melt-in-your-mouth texture with a peppery crust.
• Quick to cook—just a few minutes in the pan!
• Fresh, zingy sauce adds a punch of flavor without overpowering the fish.
• Naturally low-carb and high-protein, perfect for healthy eating.
• Elegant enough for entertaining, easy enough for weeknights.

What Is Tuna Steak?

Tuna steak is a thick cut of fresh tuna, often from yellowfin or ahi varieties, known for its meaty texture and rich flavor. Unlike flaky white fish, tuna has a bold, steak-like quality that stands up to searing. Popular in Mediterranean and Asian cuisines, it’s often served rare to medium-rare to preserve its tenderness. This version features a spice-crusted exterior and a zesty mustard-parsley sauce that complements the tuna’s natural umami.

Pro Tips for the Best Tuna Steak

• Don’t overcook it: Tuna is best served rare or medium-rare—just sear it for about 1–2 minutes per side.
• Use high-quality fresh tuna: Look for steaks that are firm, with a deep red color and no strong fishy smell.
• Crush spices coarsely for a rustic, textured crust.
• Let it rest briefly before slicing to keep juices in.
• Use a very hot pan: This helps develop a quick crust without drying out the inside.

Frequently Asked Questions

What’s the Ideal Doneness for Tuna Steak?

Tuna is best served seared on the outside and pink in the center—about rare to medium-rare. Overcooking makes it dry and chewy.

Can I Use Canned Tuna Instead?

No, this recipe is specifically for fresh tuna steaks. Canned tuna won’t hold up to searing or deliver the same texture.

What Can I Use Instead of Mustard Powder?

You can substitute with a teaspoon of Dijon mustard, but reduce the vinegar slightly to balance acidity.

Is This Recipe Suitable for Meal Prep?

Yes! Sear the tuna ahead and store it in the fridge. Add the sauce just before serving for best flavor and texture.

Can I Grill the Tuna Instead?

Absolutely. Preheat your grill to high and sear the tuna for 1–2 minutes per side. Brush with oil to prevent sticking.

How to Store Tuna Steak

Allow the cooked tuna to cool completely, then transfer to an airtight container. Store in the refrigerator for up to 2 days. To reheat, gently warm in a skillet over low heat or enjoy it cold—tuna steak is excellent in salads or sandwiches the next day.

How to Freeze Tuna Steak

You can freeze raw tuna steaks before marinating. Wrap each piece in plastic wrap, then foil, and store in a freezer bag for up to 3 months. Thaw overnight in the fridge. It’s not recommended to freeze cooked tuna, as it tends to dry out upon reheating.

How to Make Seared Tuna Steak with Mustard-Parsley Sauce

Step 1

Step 1

In a mortar and pestle, coarsely crush the white peppercorns and coriander seeds.

In a mortar and pestle, coarsely crush the white peppercorns and coriander seeds.

Step 2

Step 2

Rub the spice mixture over the tuna steaks. Drizzle with olive oil, cover, and marinate in the fridge for 1 hour.

Rub the spice mixture over the tuna steaks. Drizzle with olive oil, cover, and marinate in the fridge for 1 hour.

Step 3

Step 3

Heat a pan over high heat. Add a splash of olive oil. Sear the tuna steaks for 1–2 minutes per side, until golden crust forms but the center stays pink.

Heat a pan over high heat. Add a splash of olive oil. Sear the tuna steaks for 1–2 minutes per side, until golden crust forms but the center stays pink.

Step 4

Step 4

In a food processor or blender, combine olive oil, vinegar, salt, mustard powder, and parsley. Blend until smooth.

In a food processor or blender, combine olive oil, vinegar, salt, mustard powder, and parsley. Blend until smooth.

Step 5

Step 5

Slice the tuna into thick pieces, drizzle with the mustard-parsley sauce, and serve immediately.

Slice the tuna into thick pieces, drizzle with the mustard-parsley sauce, and serve immediately.