Keto Blackened Salmon
Flaky salmon fillets crusted in a smoky, spicy Cajun blend and seared in butter until charred and crisp. At just 1.4g net carbs per serving and ready in 20 minutes, this restaurant-style keto dinner is fast, foolproof, and packed with healthy fats.
Head of Nutrition · June 18, 2026
Nutrition per serving
Per serving · makes 4. Values are estimates; brands vary.
This keto blackened salmon delivers bold Cajun flavor in just 20 minutes: flaky fillets crusted in a smoky, spicy spice blend and seared in butter until deeply charred. With only 1.4g net carbs per serving and 34g of protein, it's a fast, satisfying weeknight dinner that tastes like it came from a restaurant.
Ingredients
- 4 salmon fillets (about 6 oz each), skin on or off
- 2 tbsp smoked paprika
- 1.5 tsp garlic powder
- 1.5 tsp onion powder
- 1 tsp dried thyme
- 1 tsp dried oregano
- 1 tsp cayenne pepper (adjust to taste)
- 1 tsp salt
- 1/2 tsp black pepper
- 3 tbsp unsalted butter
- 1 tbsp olive oil
- 1 lemon, cut into wedges, for serving
Instructions
- 1
In a small bowl, combine the smoked paprika, garlic powder, onion powder, thyme, oregano, cayenne, salt, and black pepper to make the blackening seasoning.
- 2
Pat the salmon fillets completely dry with paper towels. Rub the seasoning generously over all sides of each fillet, pressing it in to form an even crust.
- 3
Heat the olive oil and 2 tablespoons of the butter in a large cast-iron skillet over medium-high heat until the butter is foaming and just beginning to brown.
- 4
Place the fillets flesh-side down in the skillet and sear undisturbed for 3-4 minutes, until a dark, crisp crust forms. Flip carefully and add the remaining 1 tablespoon butter, spooning it over the fish.
- 5
Cook for another 3-4 minutes, until the salmon flakes easily and reaches an internal temperature of 125-130°F (52-54°C) for medium. Thinner fillets will cook faster.
- 6
Transfer to plates and serve immediately with lemon wedges and the buttery pan juices spooned over the top.
Tips & notes
- Cast iron gives the best char, but any heavy oven-safe skillet works. Make sure the pan is fully preheated so the crust forms quickly without overcooking the inside.
- Blackening produces smoke, so turn on your range hood or crack a window. For a milder version, cut the cayenne to 1/2 teaspoon or swap in extra paprika.
- Store leftovers in an airtight container in the fridge for up to 3 days. Reheat gently in a low oven or enjoy cold flaked over a salad to avoid drying out the fish.
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Frequently asked questions
- How many carbs are in keto blackened salmon?
- Each serving has just 1.4g net carbs (2.3g total carbs minus 0.9g fiber), plus 398 calories, 34g protein, and 28g fat. This recipe makes 4 servings, making it an excellent fit for a ketogenic or low-carb diet.
- What is blackening seasoning made of?
- Blackening seasoning is a Cajun-style spice blend of smoked paprika, garlic powder, onion powder, thyme, oregano, cayenne, salt, and black pepper. It's naturally keto and gluten-free with virtually no carbs, and the high heat caramelizes the spices into a dark, flavorful crust.
- How do I keep the salmon from sticking to the pan?
- Pat the fillets very dry, use a hot, well-oiled cast-iron skillet, and don't move the fish once it hits the pan. The crust needs 3-4 minutes to form and release naturally — if it resists when you try to flip, give it another minute.
