Easy Keto Diet Recipe: Delicious and Healthy Grilled Tuna Steak

Indulge in Keto-Friendly Grilled Tuna Steak

When it comes to a meal that’s as nutritious as it is delectable, few dishes can hold a candle to the Grilled Tuna Steak. This keto-friendly powerhouse is not just a feast for your taste buds but also aligns perfectly with your low-carb dietary goals. Packed with high-quality proteins and essential fats, it’s the kind of meal that keeps you satiated and energized without any carb crash.

Why is this recipe a stellar choice for those on a ketogenic diet? Tuna steak is naturally low in carbohydrates and high in fats, making it an excellent protein source that fits within the macronutrient ratios required for ketosis. Whether you’re looking for a satisfying lunch or a hearty dinner, this grilled tuna steak is sure to impress.

Succulent Grilled Tuna Steak

The Heart of the Sea on Your Plate

My love for the Grilled Tuna Steak began on a quaint seaside town where the local fishermen would haul in the freshest catch each morning. The simplicity of grilling the fish with just a few herbs and spices unveiled the true essence of the ocean’s bounty. This recipe is a tribute to those early mornings by the docks, where the aroma of grilled seafood was as invigorating as the salty sea breeze.

Each ingredient in this recipe has been chosen for its ability to complement the tuna’s rich flavor while also catering to the keto lifestyle. Olive oil, a staple in the keto diet, brings a dose of healthy fats and ensures a perfectly seared steak. The fresh lemon juice adds a zesty tang that cuts through the richness, while garlic and herbs like parsley and oregano infuse the fish with aromatic depth.

For those following a ketogenic diet, it’s essential to prioritize ingredients that contribute to your daily macros. This grilled tuna steak recipe does just that, with a balance of fats and proteins to help maintain ketosis. Plus, the minimal carb content means you can enjoy this dish without worry.

Keto Tuna Steak Preparation

Perfecting the Grilled Tuna Steak

Grilling tuna steaks is an art that requires attention to detail. The key to a succulent steak lies in the preheating of your grill. A high temperature of around 400°F is crucial for achieving that desirable sear without overcooking the fish. Remember, tuna steaks are best enjoyed medium-rare to retain their moisture and flavor.

When marinating, ensure each steak is well-coated and allowed to sit for at least 5 minutes. This brief pause lets the flavors meld and penetrate the fish, promising a more robust taste with each bite. Use tongs to carefully flip the steaks, and always oil your grill grates beforehand to prevent sticking.

My pro tip for an extra flavor boost is to add a sprig of rosemary to the grill while cooking. The smoke infuses the tuna with a subtle woody aroma that’s simply divine. And for those who love a bit of heat, feel free to be generous with the red pepper flakes. It’s all about personalizing the dish to your palate while keeping it keto-friendly.

Grilled Tuna Steak Ready to Serve

Variations to the Grilled Tuna Steak

Herb-Crusted Tuna Steak

For a textural twist, create a crust using finely chopped almonds mixed with herbs. Pat this mixture onto the steaks before grilling for a delightful crunch that complements the tender fish.

Cajun-Style Tuna Steak

Spice things up with a Cajun seasoning blend. The smoky and spicy flavors will transport your taste buds straight to the heart of New Orleans, all while keeping it low-carb.

Mediterranean Tuna Steak

Top your grilled tuna with a mix of diced olives, feta cheese, and cucumbers for a Mediterranean flair. The salty olives and feta balance the fresh, crisp cucumbers, creating a harmonious topping for your keto-friendly steak.

Substitutions for Your Keto Grilled Tuna Steak

If olive oil isn’t your preference, avocado oil is a great substitute that offers a similar profile of healthy fats and a high smoke point, perfect for grilling. For those who can’t find fresh tuna, salmon steaks make an excellent alternative, offering omega-3 fatty acids essential for a keto diet. And if you’re out of fresh lemon juice, apple cider vinegar can provide the necessary acidity to brighten up the dish.

Frequently Asked Questions

Can I use frozen tuna steaks for this recipe?
Yes, frozen tuna steaks can be used, but ensure they are fully thawed and patted dry before marinating to achieve the best flavor and texture.

How do I know when my tuna steak is done?
A medium-rare tuna steak will have a slightly pink center. It’s done when the outside is well-seared, and the inside remains tender, typically after 3 minutes per side on a hot grill.

What sides pair well with grilled tuna steak?
Keto-friendly sides like sautéed spinach, cauliflower rice, or a fresh arugula salad complement the richness of the tuna steak.

How long can I marinate the tuna steaks?
For the best results, marinate for at least 5 minutes and up to 30 minutes. Avoid marinating for too long as the acidity from the lemon juice can start to “cook” the fish.

Can I grill the tuna steak indoors?
Yes, you can use a grill pan on the stove. Ensure it’s very hot before adding the tuna steaks to mimic the high heat of an outdoor grill.

Succulent Grilled Tuna Steak

Indulge in a succulent grilled tuna steak, seasoned with a harmonious blend of herbs and spices, seared to perfection. This keto-friendly recipe offers a perfect balance of protein and healthy fats, ideal for a satisfying lunch or dinner.
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Prep Time 10 minutes
Cook Time 6 minutes
Total Time 16 minutes
Course Dinner
Cuisine American
Servings 2 servings
Calories 310 kcal


  • Grill
  • Small bowl
  • Whisk
  • Shallow dish
  • Tongs


  • 2 Tuna steaks each 6 ounces or 170 grams
  • 2 tbsp Olive oil
  • 1 tbsp Fresh lemon juice
  • 2 cloves Garlic, minced
  • 1 tbsp Fresh parsley, chopped
  • 1 tsp Dried oregano
  • ½ tsp Salt
  • ¼ tsp Ground black pepper
  • ¼ tsp Crushed red pepper flakes optional


  • Preheat your grill to high heat, approximately 400°F (204°C).
  • In a small bowl, whisk together olive oil, lemon juice, minced garlic, chopped parsley, oregano, salt, black pepper, and red pepper flakes (if using) to create the marinade.
  • Place the tuna steaks in a shallow dish and pour the marinade over them, ensuring both sides are well-coated. Let the steaks marinate for 5 minutes.
  • Once the grill is hot, oil the grill grates to prevent sticking. Place the marinated tuna steaks on the grill.
  • Grill the tuna steaks for about 3 minutes on each side for medium-rare, or longer if you prefer more well-done fish.
  • Remove the tuna steaks from the grill and let them rest for a couple of minutes before serving.


Tuna steak is best enjoyed medium-rare to preserve its moisture and flavor. If overcooked, it can become dry and tough.
Always ensure your grill is hot before cooking to get a good sear on the steaks.
Feel free to adjust the level of heat by increasing or decreasing the amount of red pepper flakes.


Calories: 310kcalCarbohydrates: 1gProtein: 44gFat: 14gFiber: 0.2gNet Carbs: 0.8g
Keyword Grilled Tuna Steak, Healthy Seafood Recipe, Keto Tuna Steak, Low Carb Grilled Fish
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