There’s something undeniably classy about starting a meal with perfectly seared Ahi tuna.
Ruth’s Chris Steak House knows how to set the tone with this dish — lightly crusted, rare in the center, sliced thin, and paired with a punchy mustard sauce and tangy vinaigrette. It’s elegant, fresh, and surprisingly easy to replicate at home.
This recipe captures everything you love about their signature appetizer. It’s quick enough for weeknights, fancy enough for date night, and it comes together in under 20 minutes with bold flavor and effortless style.
Why You’ll Love This Recipe
If you’ve ever felt intimidated by cooking tuna at home — don’t! This dish uses sushi-grade Ahi tuna, lightly seasoned and seared for less than a minute on each side. The result is buttery, tender slices with a crisp crust and that signature rare center.
And the sauces? They’re the magic. A creamy, spicy mustard sauce and a sesame vinaigrette give it the restaurant feel — perfect for dipping or drizzling over each delicate slice.
What You’ll Need
For the Tuna:
- 1 (8 oz) sushi-grade Ahi tuna steak (about 1-inch thick)
- 1 tablespoon sesame oil
- 1 tablespoon soy sauce
- 1 tablespoon black and white sesame seeds (mixed)
- Kosher salt and black pepper, to taste
For the Mustard Sauce:
- ¼ cup Dijon mustard
- 2 tablespoons mayonnaise
- 1 tablespoon honey
- 1 teaspoon soy sauce
- 1 teaspoon lemon juice
For the Vinaigrette:
- 2 tablespoons rice vinegar
- 1 tablespoon soy sauce
- 1 tablespoon sesame oil
- 1 teaspoon honey or sugar
- ½ teaspoon grated fresh ginger
Garnish:
- Microgreens or chopped green onions
- Optional: wasabi or pickled ginger
Pro Tips
- Use sushi-grade tuna — this dish is served rare, so freshness is essential.
- Pat the tuna dry before seasoning to get the best crust during searing.
- Let the skillet get very hot before adding the tuna — the quick sear locks in flavor.
- Slice with a very sharp knife to keep those clean, elegant pieces.
- Chill the mustard sauce and vinaigrette for 10 minutes before serving for best flavor.
Tools You’ll Need
- Nonstick or cast iron skillet
- Small bowls and whisk for sauces
- Tongs or fish spatula
- Sharp chef’s knife
- Cutting board
- Serving plate
Substitutions and Variations
- Tuna: Can’t find sushi-grade tuna? Use cooked shrimp or lightly grilled salmon.
- Sauces: Swap Dijon mustard for whole grain, or add sriracha for spice.
- Vinaigrette: Try using lime juice instead of vinegar for a citrusy twist.
- Add-ins: Serve over seaweed salad or cucumber ribbons for a fuller appetizer.
Make Ahead Tips
Both sauces can be made up to 3 days in advance and stored in the fridge. The tuna should be seared just before serving for best texture and temperature, but you can marinate it up to 1 hour ahead.
Instructions
1. Make the Mustard Sauce
In a small bowl, whisk together Dijon mustard, mayonnaise, honey, soy sauce, and lemon juice until smooth. Chill until ready to serve.
2. Make the Vinaigrette
In another bowl, combine rice vinegar, soy sauce, sesame oil, honey, and grated ginger. Whisk until fully emulsified.
3. Prep the Tuna
Pat the tuna dry with paper towels. Brush with sesame oil and soy sauce. Season with salt and pepper, then press sesame seeds onto both sides.
4. Sear the Tuna
Heat a skillet over high heat. When hot, sear the tuna for 30–45 seconds per side until just browned but still rare in the center. Remove and let rest for 1 minute.
5. Slice and Serve
Using a very sharp knife, slice the tuna thinly, about ¼ inch thick. Fan slices on a plate, drizzle with mustard sauce and vinaigrette, and garnish with microgreens.
Leftovers and Storage
This appetizer is best served fresh. If you do have leftovers, store the tuna tightly wrapped in the refrigerator for up to 1 day.
The sauces can be refrigerated separately for up to 3 days. For food safety, do not consume seared rare tuna after 24 hours.
Recipe FAQs
Q: What does “sushi-grade” tuna mean?
It means the fish is safe to eat raw and has been handled and frozen according to specific food safety standards. Always ask your fishmonger to confirm.
Q: Can I use frozen tuna?
Yes — just make sure it’s sushi-grade and fully thawed before cooking.
Q: What’s the best way to slice tuna cleanly?
Use a very sharp knife and wipe the blade between slices for the cleanest presentation.
Q: Is this dish served hot or cold?
It’s best served slightly warm or room temperature, right after searing. The sauces can be cool for contrast.
Elegant, Fresh, and Bursting with Flavor
This Ruth’s Chris–Inspired Ahi Tuna Appetizer proves that you don’t need a steakhouse reservation to enjoy high-end flavor at home.
With a quick sear, bold sauces, and a beautiful presentation, it’s the kind of dish that makes any meal feel special — without the fuss.
Try it at your next dinner party, date night, or even just as a treat for yourself. Let me know how it went in the comments! Did you adjust the sauces or add your own twist? I’d love to hear how you made it your own.