This grilled blackened grouper with avocado crema is robust in flavor, absolutely delicious and comes together in mere minutes. The grouper is tender on the inside with a beautiful blackened crust on the outside that has just the right amount of spice. We serve the grouper with a creamy, tangy and luscious avocado sauce that is cooling, complementing the blackening seasoning perfectly. This grouper dish is perfect for a no-fuss summer dinner that the whole family – (and guests!) will love.

An overhead image of a filet of blackened grouper on a white plate with avocado crema and a lime wedge.

Thank you to my friends at the Aquaculture Stewardship Council for sponsoring this post in an effort to build awareness about responsible seafood and thanks to you, my readers, for supporting brands that help keep Jenny Shea Rawn running. As always, all opinions are my own. 

BLACKENING SEAFOOD

Blackening is one of my favorite ways to enjoy fish – especially grouper and mahi mahi. Blackening involves coating the fish with a blend of herbs and spices before searing it – usually in a hot skillet (but, in this case, we are cooking the fish on the grill). The seasoning creates a dark, flavorful crust while preserving the tenderness of the fish. Typically, blackening involves some combination of onion powder, garlic powder, oregano, thyme, cayenne (optional), paprika, black pepper and salt. I am very sensitive to heat, so I tend to omit the cayenne when I blacken fish, but if you love heat, add a small pinch of cayenne. When cooking the fish, the high heat of the grill toasts the spices and imparts a nice smokiness.

Part of the magic of blackening is the combination of the spices and herbs with heat and butter. Since we are blackening on the grill, we are not cooking the fish in butter, but will brush salted butter over the fish once we take it off the grill. Then we top the grouper with the avocado crema and serve with plenty of lime wedges.

WHAT IS AVOCADO CREMA?

Avocado crema is a creamy, tangy, and luscious sauce that adds a delightful touch to a wide range of dishes. It may sound fancy, but it’s very simple to whip up with just a few ingredients, including: avocado, sour cream (or plain yogurt), lime juice, garlic and cilantro. Whether used as a dip, a topping, or a dressing, its rich and tangy flavors complement so many dishes – especially seafood dishes. In this blackened grouper recipe, the mild and smooth avocado crema helps cool down the heat from the blackening seasoning.

An image of avocado crema in a white bowl with a half lime on the side

ABOUT THIS GROUPER

The grouper that we are using comes from Aqquua, an ASC-certified grouper farm that is passionate about raising the highest quality marine finfish. Aqquua grouper is certified by the Aquaculture Stewardship Council (ASC), meaning it’s been raised with care according to the world’s highest standards for environmentally sustainable and socially responsible aquaculture. Whether you’re shopping for grouper, shrimp, salmon or other farmed seafood, ASC’s sea green label is the best way to know where your farmed seafood comes from, how it was raised and how it got to you.

An image of raw grouper fillets, skin side up on a white plate.

ASC CERTIFICATION

So, how do you know if your seafood is ASC certified? Look for the label! Sea Green. Be Green. For more information about ASC certification and to learn why shopping for seafood with the ASC’s sea green label is the most responsible choice, follow ASC on Instagram and visit their website at SeaGreenBeGreen.com.

Back to blackening this grouper.

Don’t let this list of ingredients for the blackening seasoning scare you, I bet you have all of these spices and herbs in your spice drawer.

INGREDIENTS YOU NEED

  • grouper fillet
  • salted butter

Blackening seasoning:

  • onion powder
  • paprika
  • garlic powder
  • dried oregano
  • dried thyme
  • kosher salt
  • ground black pepper
  • cayenne pepper (optional)

Avocado crema:

  • avocados
  • sour cream or plain whole milk yogurt
  • fresh lime juice
  • garlic
  • cilantro

INSTRUCTIONS FOR MAKING THIS BLACKENED GROUPER

Full instructions are in the recipe card below, but here’s a summary:

  • Make the avocado crema by adding the avocado to a high speed blender or food processor with the sour cream or yogurt, lime juice, garlic, cilantro and a pinch of salt and pepper. Blend until smooth. Taste and season with more salt and pepper, if needed. Transfer to a small bowl.

Avocado crema ingredients on a white plate

Ingredients for avocado crema in a food processor

An image of avocado crema in a food processor

  • Preheat the grill to high heat. Clean and oil the grates.
  • Using a paring knife, slice a few shallow slits in the grouper skin to prevent it from curling up when placed on the grill.
  • Mix together the herbs and spices for the blackening seasoning. Pat the fish very dry with a paper towel. Generously coat the grouper with the seasoning, ensuring an even distribution.

Blackening seasoning on a white plate

An image of blackening seasoning

An image of raw grouper fillets

An image of grouper with blackening season on a plate prior to grilling.

  • Reduce grill heat to medium high. Place the fillets on the grill. Cook 2-3 minutes on each side until the fish flakes easily. A dark crust should form with the grill marks on the flesh side of the fillet. Do not overcook.

An image of blackened grouper on the grill.

  • Remove fish from heat, brush with butter, sprinkle with sea salt and serve with avocado crema and lime wedges.

RECIPE FAQS:

What does grouper taste like?

Grouper is a mild flaky white fish – it has a subtle, yet distinct flavor. It’s a versatile fish, pairing well with a variety of seasonings and preparation methods.

Can you substitute guacamole for the avocado crema?

Yes – if you’re short on time and have guac already made, feel free to sub that for the avocado crema. The avocado crema is milder flavored, allowing the fish to shine, so we prefer it to a stronger flavored guacamole.

How do you blacken fish?

Blackening fish is easier than you’d think. You simply combine a handful of spices (that you probably already have in your spice cabinet), rub it on the fish, then grill and brush with salted butter (or pan fry in butter).

What should you serve this blackened grouper with?

We love to serve this grouper with a big leafy green salad and warm whole grain rolls. It would also be great with rice and any grilled veggies.

Looking for more great summer seafood recipes?

Lobster Tacos

Salmon Kale Salad

Surf and Turf Platter

An image of 4 grilled and blackened grouper fillets on a white plate.

Here’s how to make this blackened grouper:

Blackened Grouper

This grilled blackened grouper with avocado crema recipe is robust in flavor, absolutely delicious and comes together in mere minutes. The grouper is tender on the inside with a beautiful blackened crust on the outside that has just the right amount of spice. We serve the grouper with a creamy, tangy and luscious avocado sauce that is cooling, complementing the blackening seasoning perfectly.
Total Time 15 minutes
Course Main Course
Cuisine American
Servings 4
Calories 412 kcal

Ingredients
  

For the avocado crema

  • 2 ripe avocados
  • 1/4 cup sour cream or sub whole milk yogurt
  • 1/4 cup fresh cilantro leaves roughly chopped
  • 1 1/2 limes juice from
  • 1 clove garlic minced
  • 1/2 teaspoon kosher salt
  • 1/4 teaspoon black pepper

For the grouper

  • 24 ounces grouper fillet (if frozen, thawed), skin-on, cut into 4 fillets
  • 1 tsp onion powder
  • 1 tsp paprika
  • 1 tsp garlic powder
  • 1 tsp dried oregano
  • 1 tsp dried thyme
  • 1/2 tsp kosher salt
  • 1/4 tsp ground black pepper
  • 1/8 tsp cayenne pepper optional

For serving

  • 2 tbsp salted butter melted
  • flaky sea salt
  • lime wedges

Instructions
 

  • Add the avocado flesh into a high speed blender or food processor with the sour cream or yogurt, cilantro, lime juice, garlic, plus a pinch of salt and pepper. Blend until smooth. Taste and season with more salt and pepper, if needed. Transfer to a small bowl.
  • Preheat the grill to high heat. Clean and oil the grates.
  • Using a paper towel or kitchen towel, pat the grouper very dry on both sides. This will help the fish develop a nice crust. Using a paring knife, slice a few shallow slits in the grouper skin to help prevent it from curling up when placed on the grill.
  • Combine onion powder, paprika, garlic powder, oregano, thyme, salt, pepper and cayenne (if using) together in a small bowl. Mix well. Generously coat the grouper with the seasoning, ensuring an even distribution. Press the seasoning into the fish.
  • Reduce grill heat to medium high. Place the fillets on the grill. Cook 2-3 minutes each side until the fish flakes easily with a fork. Cooking time will vary depending on the thickness of the fillets – these fillets here were very thin. A dark crust should form with the grill marks on the flesh side of the fillet. Do not overcook.
  • Remove fish from heat. Brush with melted butter and sprinkle with sea salt. Add a scoop of avocado crema on the side. Serve with lime wedges.

Notes

  • Grouper is cooked through when the internal temperature reaches 140 degrees F in the center of the thickest part of the fillet, as measured with a meat thermometer. It will continue to rise to a safe internal temperature of 145 degrees F when removed from heat. Fish will have turned from translucent flesh to white and opaque throughout and will flake easily with a fork.
  • Leftover avocado crema is wonderful served on any grilled seafood, veggies, drizzled on salads, served in tacos or quesadillas … or by the spoonful!
  • Store the leftover avocado crema in an airtight container in the refrigerator. It’s best to consume it within 2-3 days to ensure optimal freshness and flavor.

Nutrition

Calories: 412kcalCarbohydrates: 14gProtein: 36gFat: 25gSaturated Fat: 8gPolyunsaturated Fat: 3gMonounsaturated Fat: 12gTrans Fat: 0.2gCholesterol: 86mgSodium: 730mgPotassium: 1392mgFiber: 8gSugar: 2gVitamin A: 819IUVitamin C: 20mgCalcium: 101mgIron: 3mg
Keyword Blackened Grouper
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An image of blackened grouper on a white plate with lime wedges and avocado crema.