Blackened Grouper Fish Sandwiches with Dill Tartar Sauce
on Aug 27, 2025
This post may contain affiliate links! For more info, check out our privacy policy.
These Blackened Grouper Fish Sandwiches are cooked and assembled in under 30 minutes and served with a Dill Tartar Sauce. They are bold, smoky, and balanced, making this a special sandwich for any occasion.
If you’re looking for more fish recipes, be sure to check out our 20 Minute Miso Salmon (In the Oven) and Tuna Nicoise Salad with Mustard Vinaigrette.
Why You’ll Love This Recipe
You’ll love this recipe for its bold flavors, paired with a creamy tartar sauce, all on a brioche bun!
- Has a nice texture from the flaky fish, paired with the creamy tartar sauce and the crunch from the lettuce
- Comes together in under 30 minutes
- Uses one pan to toast your buns and cook your fish
Recipe Ingredients
Below are the ingredients you need to make this recipe, including all our tips and substitutions.
- White Fish Fillets: We are using grouper for this fish sandwich. It holds up really nicely when seared and doesn’t fall apart. Other great options are rockfish or mahi-mahi.
- Seasoning: The seasoning is a blend of smoked paprika, garlic powder, dried oregano and thyme, cayenne pepper, kosher salt, and freshly ground black pepper.
- For the sandwiches: We keep it simple with buttered toasted brioche buns, fresh Dill Tartar Sauce, tomato slices, and butter lettuce.
The full list of ingredients with exact quantities can be found on the recipe card below.
Tips and Substitutions
- If you don’t have grouper, other great options are rockfish or mahi-mahi.
- Wait to add the spread to the buttered hot brioche buns. This helps keep the buns crisp and the spread firm.
- Storing and Prepping: You can season your fish ahead of time before cooking, or you can also refrigerate cooked fish and use it within 2 days.
How to Make Blackened Fish Sandwiches
Step 1: Whisk together the tartar sauce ingredients. Make your spice mixture and rub it on all sides of the fish.
Step 2: Toast your buns in a large skillet with butter and remove.
Step 3: Heat oil in the same pan and sear the fish.
Step 4: Assemble your sandwich by layering tartar sauce, lettuce, tomato, fish, and more sauce. Serve!
The full detailed instructions can be found on the recipe card below.
Serving Recommendations
Looking for some ideas to serve with these blackened fish sandwiches? We have you covered!
- Serve alongside our Grilled Corn with Tajin Lime Butter and Parmesan Sweet Potato Fries.
- Pair with a salad, such as our Easy Melon Prosciutto Salad with Mint or Citrus Avocado Salad with Chili Crisp.
- Host a party with Prosciutto and Melon and Easy Chimichurri Mayo Potato Salad.
Blackened Fish Sandwiches FAQs
Yes, you can air fry blackened fish! Preheat your air-fryer to 400 degrees F. Cook until flaky and slightly crisp and charred.
You can serve blackened fish on its own, with rice, in a salad, or in this recipe, in a sandwich with tartar sauce.
The best fish to blacken is a fish that has a firmer texture, so it doesn’t fall apart during the cooking process. Some options are tuna, salmon, mahi mahi, or grouper to name a few.
This is a Cajun technique that involves rubbing the spices on the fish, where it “blackens” when it’s cooked.
More Fish Recipes
If you do make this Blackened Fish Sandwich recipe, leave a comment and give this recipe a rating, we would love to hear what you think! Don’t forget to tag us on Instagram, we love to see what you’re making! If you’d like to stay in touch and get the latest in your inbox, sign up for our Newsletter. We can also be found on YouTube, Facebook, and Pinterest!
I Wrote a Cookbook, titled Something Delicious. It includes 100 flavorful, low-fuss recipes for any time of day, and you can order it now.
Blackened Grouper Fish Sandwiches with Dill Tartar Sauce
Equipment
Ingredients
Dill Tartar Sauce
- 1/4 cup mayo
- 2 tablespoons minced fresh dill
- 1 large minced dill pickle, plus 2 teaspoons dill pickle juice
- 1 teaspoon whole grain old style mustard
- pinch of cayenne pepper, sugar, kosher salt and freshly ground black pepper
Blackened Fish Sandwiches
- 1 pound white fish fillets, about 1 pound, such as grouper, rockfish, or mahi mahi
- 1 teaspoon smoked paprika
- 1/2 teaspoon garlic powder
- 1 teaspoon dried oregano
- 1 teaspoon dried thyme
- 1/2 teaspoon cayenne pepper
- Kosher salt and freshly ground black pepper
- 1 to 2 tablespoons unsalted butter
- 4 brioche buns, halved
- 1 tablespoon extra-virgin olive oil
- sliced heirloom tomatoes
- butter lettuce leaves
Instructions
- Prepare your Dill Tartar Sauce. In a small bowl, mix mayo, dill, dill pickle, mustard, cayenne pepper, salt, pepper and sugar until completely combined.
- Make your Fish Sandwiches: Pat fish dry. In a small bowl, mix paprika, garlic powder, oregano, thyme, cayenne salt, and pepper.
- Rub the seasoning evenly over all sides of the fish. Set aside.
- In a large nonstick skillet over medium-high heat, add your butter to melt just until glistening. Add your buns to toast, cut side down, about 2 to 3 minutes. Do this in batches if needed. Set aside.
- In the same skillet on the same heat, add in your fish and sear for 2 to 3 minutes per side, until golden, charred, blackened, and cooked through. It should be opaque, remove, and do this in batches if needed.
- Assemble your sandwich, layer your tartar sauce, cooked fish, lettuce, tomato, and more spread. Serve and enjoy!
Notes
- If you don’t have grouper, other great options are rockfish or mahi-mahi.
- Wait to add the spread to the buttered hot brioche buns. This helps keep the buns crisp and the spread firm.
- Storing and Prepping: You can season your fish ahead of time before cooking, or you can also refrigerate cooked fish and use it within 2 days.
Nutrition
Nutrition information is automatically calculated, so should only be used as an approximation.
I LOVE this blackened fish sandwich recipe and it comes together in under 30 minutes! Enjoy!
love it ! so yummy. my boyf and i are addicted. made it one time w mahi mahi and one with cod. tip: dont do the cod. just fell apart and didnt hold onto the flavor as well.
So happy you enjoyed!! Thanks for your review!