Prepare Pesto before cooking the fish. Set it aside.
For the Flounder:
Preheat the oven to 325°F (162°C). Then, combine the melted butter, parsley, salt, pepper, and red pepper flakes in a small bowl.
Line the filets in a prepared baking dish, and brush them with the butter mixture using a pastry brush.
Bake for 10-20 minutes. Cooking time may vary depending on the thickness of the filets.
Top the baked flounder with homemade pesto and serve with a house salad or pilaf.
Notes
How long should I cook the flounder?
If using thin filets, I recommend checking for doneness at the 10-minute mark. Thicker cuts of flounder may take longer. Consider baking those for 20-25 minutes and check them at the 20-minute mark.
Nutrition Disclosure:
The nutritional information shown is an estimate provided by an online nutrition calculator. It should not be considered a substitute for professional advice.