Blackened Flounder with Cajun Sauce

Blackened flounder fillets are tender and flakey on the inside and browned and crispy on the outside. Seasoned with a spice combination that is smokey and a bit spicy, the flounder will be extra special served with a smoky cajun sauce.

My family can't resist the rich flavors from blackening seasonings. Add to that a really quick cooking method that guarantees a crispy crust, it's no surprise I've created many blackened recipes! Try some of these: Chilean sea bass,  Snapper, Grouper, Cod and Swordfish. And we love eating blackened fish with a tasty sauce alongside.

Ingredients

You will need the following ingredients to make this easy flounder recipe:

Ingredient Notes & Substitutions

I am using frozen fish, defrosted overnight in the refrigerator. Choosing fresh is always preferable, if possible. Look for fillets that have firm, not mushy flesh, a mild, sea smell. Store in the refrigerator and use within 2 days.

This recipe offers 4 flounder fillets. These should all fit in one layer spread out in the skillet. If you are making more fish, cook them in separate batches. Place on paper towel-lined plate and cover with foil.

How to Cook Blackened Flounder Fillets

Step 1:  Stir together the seasonings.  Pat the fillets dry, rub each with some olive oil and press the seasonings onto the top an bottom of fish.

Step 2: Heat a cast iron or other skillet over medium-high heat.  Place butter in pan and swirl around.  Place fish in skillet and cook for 3 minutes.  If pan begins to smoke, turn down heat to medium or low-medium.  But you do want the fish to brown on each side.

Step 3: Don't move the fish for at least 3 minutes.  Use a metal spatula and slide underneath to flip over.  If the fish is sticking, let it cook another minute. The flounder is done when it is golden brown and flakey.  An internal meat thermometer registers at least 145°F.  

How to Make Cajun Dipping Sauce

Whisk together mayonnaise, sweet chili sauce, white vinegar, lemon juice, chili powder, onion powder, salt, pepper. You can mix it in a mini processor, food bullet or coffee grinder. That will make the sauce extra smooth. If you don't have these, just mix really well with a wire whisk. Store in the refrigerator until ready to serve.

If you would like to try a different sauce with this recipe, I suggest trying my Baja sauce, Lemon herb sauce, Red pepper sauce or Lemon Butter sauce.

Recipe Tips

Once fish is in the hot pan, don't move it for at least 3 minutes. Carefully slide a metal spatula underneath. The fish should have some give to it, not sticking to pan. If it is, let it cook another 1 minute and check again before trying to flip it.

Flounder cooks quickly. Overcooking it can cause fish to turn rubbery in texture. Always test the fish at the time listed. If you fish is on the thin, test 1 minute sooner. If on thicker side, test 1 minute later.

Side Dishes to Serve With Blackened Flounder

These veggie dishes are easy to make and go along really well with flounder recipes. They are not heavily seasoned so as not to compete with the flavors of the fish or the the sauce.