Preheat oven to 400F and lightly grease a large sheet pan. Set aside for a moment.
In a large bowl, combine potatoes, green beans, butter, oregano, basil, and garlic. Season with salt and pepper to taste.
Arrange potatoes and green beans in a single layer on prepared sheet pan. Roast potatoes and green beans at 400F 20-25 minutes until vegetables are crisp-tender. Reduce heat to 375F.
Remove thawed flounder from marinade and arrange on sheet pan. Pour any remaining marinade in package over fish.
Bake flounder with potatoes and green beans at 375F an additional 15-18 minutes until flounder registers 145F with a kitchen thermometer inserted in the thickest part of fillet.
Serve flounder and vegetables warm with crusty bread for dipping in any accumulated pan sauce. Enjoy!
Notes
Storing InstructionsStore flounder, potatoes, and green beans in refrigerator up to 4 days.