Are you looking for a quick dinner idea? Try this easy pesto flounder recipe with homemade pistachio pesto! The flaky, tender fillets bake in a spiced butter mixture, and the vibrant pesto adds fresh-tasting flavor. Plus, it’s ready in 30 minutes!
Key Ingredients
- Pesto: Serve the flounder with store-bought or homemade pesto sauce. I love the nuttiness of pistachio pesto for this recipe. It combines toasted pistachios, garlic cloves, grated Parmesan cheese, fresh basil leaves, lemon juice, zest, and extra virgin olive oil.
- Flounder: Flounder has a mild flavor, and the fillets vary from delicate to firm. Fresh flounder is ideal, but frozen fillets work just as well. I buy the frozen fillets from Costco and thaw them overnight for easy prep.
- Spices: Flounder has a delicate, mild flavor that’s slightly sweet, so I season them with kosher salt, coarse black pepper, paprika, dried parsley, and red pepper flakes to warm them up a bit.
Additions and Substitutions
- Experiment with pesto flavors. Swap pistachio pesto for traditional basil pesto, walnut pesto, sun-dried tomato pesto, arugula pesto, or a nut-free version like AIP pesto.
- Spice things up. Consider using skhug or shatta sauce to top the fish for a spicier version instead of pesto.
- Experiment with mix-ins. Add a breadcrumb topping for extra texture.
How to Make Pesto Flounder
The full recipe with measurements is in the recipe card below.
Step 1: Dry toast shelled pistachios in a small skillet over low heat for 3-5 minutes.
Step 2: Transfer them to a food processor with garlic cloves, Parmesan cheese, kosher salt, red pepper flakes, lemon juice, and lemon zest. Process until crumbly. Pour the olive oil into the food processor in a single stream while processing the ingredients. Set it aside.
Step 3: Preheat the oven to 375°F (190°C). Mix the ground spices in a small bowl. Pat the flounder fillets dry with a paper towel, then coat both sides evenly with the spice mixture.
Step 4: Spread two tablespoons of pistachio pesto onto a rimmed baking sheet lined with parchment paper. Arrange the fillets in a single layer on top. Bake for 6–7 minutes.
Step 5: Remove the pan from the oven and spread more pesto over the fillets. Return to the oven and bake for another 6–8 minutes, or until the fish flakes easily with a fork and reaches an internal temperature of 145°F (63°C).
How do you know when flounder is done?
Pesto flounder will be white and flaky when it’s ready, but use a food thermometer to check the internal temperature of the fish. The safe internal temperature for flounder is 145°F (62°C).
Expert Tips
- Use a food thermometer. Cooking time for flounder will vary based on the thickness of the fillets. Use a food thermometer to check the internal temperature and cook until it reaches 145°F (62°C).
If you enjoy the pesto flounder, try more seafood recipes!
Serving Suggestions
Pesto flounder pairs well with roasted vegetables, rice, or a simple green salad. Serve it with favorites like rice pilaf, pesto ricotta pasta, air fryer zucchini and squash, risotto allo zafferano, or creamy mashed cauliflower.
What To Do With Leftovers
- Refrigerate: Store the leftover pesto flounder in an airtight container for 1-2 days.
- Reheat: Warm the leftovers in the oven or cook them in the microwave in 30-second increments.
- Repurpose: Add leftover fish to white rice or cauliflower rice to make a protein bowl. Or you can fill a warm corn tortilla with the flounder and top it with purple cabbage coleslaw and chipotle lime sauce for a quick fish taco.
More Quick Dinner Ideas:
Pesto Flounder
- Small Bowl
- ½ cup shelled pistachios
- 2 garlic cloves
- ¼ cup grated parmesan
- ½ teaspoon kosher salt
- ¼ teaspoon red pepper flakes
- lemon juice, ½ lemon, plus ½ teaspoon of lemon zest
- 3 cups basil leaves, loosely packed
- ½ cup extra-virgin olive oil
- 6-8 flounder fillets
- 1 teaspoon kosher salt
- 1 teaspoon coarse black pepper
- 1 teaspoon paprika
- ½ teaspoon dried parsley
- ½ teaspoon red pepper flakes
- ¼ cup pistachio pesto, divided
For the Pistachio Pesto:
- Dry toast the shelled pistachios in a small skillet over low heat for 3-5 minutes. Transfer them to a food processor with garlic cloves, Parmesan cheese, kosher salt, red pepper flakes, lemon juice, and lemon zest. Process until crumbly. Pour the olive oil into the food processor in a single stream while processing the ingredients. Set it aside.
For the Flounder:
- Preheat the oven to 375°F (190°C). Mix the ground spices in a small bowl. Pat the flounder fillets dry with a paper towel, then coat both sides evenly with the spice mixture.
- Spread two tablespoons of pistachio pesto onto a rimmed baking sheet lined with parchment paper. Arrange the fillets in a single layer on top. Bake for 6–7 minutes.
- Remove the pan from the oven and spread more pesto over the fillets. Return to the oven and bake for another 6–8 minutes.Tip: Pesto flounder will be white and flaky when it’s ready, but use a food thermometer to check the internal temperature of the fish. The safe internal temperature for flounder is 145°F (62°C).
- Use a food thermometer. Cooking time for flounder will vary based on the thickness of the fillets. Use a food thermometer to check the internal temperature and cook until it reaches 145°F (62°C).
Ali
Friday 26th of May 2023
Great recipe!
Tressa Jamil
Monday 2nd of October 2023
I am thrilled you enjoyed it. Thank you for taking the time to rate the recipe and leave a comment.
Emily Reynolds
Friday 26th of May 2023
This baked flounder recipe is a weeknight dinner winner!The fillets melt in your mouth, and the homemade pesto adds so much flavor. My family loved it!
Tressa Jamil
Monday 2nd of October 2023
You are so right about the fillets melting in your mouth. I may need to add that to the post. I am so happy this is a meal your whole family enjoyed.