Miniketo
ES

Keto Dinner

Blackened Tuna

There's something about the sizzle of a blackened tuna steak hitting a hot skillet that makes dinner feel special. In my kitchen, this keto-friendly dish comes together in minutes, coating thick cuts of tuna with bold Cajun spices and a buttery sear. It's the kind of meal that turns a weeknight into a celebration without any of the fuss.

5 min Prep time 8 min Cook time 13 min Total time 4 Servings 310 Calories
Blackened Tuna

Ingredients

  • /2 pounds fresh tuna steaks (1 inch thick)
  • tablespoons Cajun seasoning
  • tablespoons olive oil
  • tablespoons butter

Instructions

  1. Step 1

    Start by patting the tuna steaks completely dry with paper towels—this helps achieve that perfect blackened crust. Generously coat both sides with Cajun seasoning, pressing gently so it adheres. Set a large skillet over high heat and add the olive oil and butter. The moment the oil begins to shimmer and the butter sizzles, carefully place the steaks in the pan. I usually listen for that first loud hiss—it tells me the heat is just right. Let them cook undisturbed for 3 to 4 minutes until the underside develops a dark, charred crust. Flip only once and cook for another 3 to 4 minutes. For medium-rare, the center should still have a cool, ruby-red core. If you prefer well-done, give it an extra minute per side. The total cook time rarely exceeds 8 minutes for one-inch steaks. Remove them from the pan and let rest for a couple of minutes before slicing. A quick squeeze of lemon brightens everything, and dinner is served.

Chef's Tip

My secret is to let the tuna come to room temperature for 15 minutes before cooking. Cold steaks can seize up and won't sear evenly. Also, don't move them around in the pan—that dark crust only forms when they sit still.

Storage Tips

Store leftover tuna in an airtight container in the fridge for up to 2 days. Reheat gently in a skillet over low heat to avoid drying out, or flake it cold over a salad.

Variation Tips

For a milder heat, use a blackening spice blend or smoked paprika instead of Cajun seasoning. Pair the tuna with buttery cauliflower mash or a crisp cucumber avocado salad. You can also slice it and serve over mixed greens with ranch dressing for a quick lunch.

Frequently Asked Questions