The thing that makes this easy grilled flounder easy is a reusable, nonstick grilling mat. Flounder is very tender, and the filets are uneven in thickness. You’ll only need to grill it on one side! Because of its delicate nature, direct cooking will only take a few minutes, so the other parts of your menu need to be complete when you start cooking the fish. We love this with a simple baked sweet potato and a green salad.