Get ready. Set a rack in the middle of your oven and preheat to 425°F. Lightly brush a sheet pan with thin layer of olive oil.
Season the halibut fillets. Sprinkle
the fish all over with salt and pepper (about ½ to ¾ teaspoon each),
Italian seasoning, garlic powder, and Aleppo pepper or red pepper flakes
(if using). Arrange on the prepared sheet pan.
Roast.
Drizzle the fish with extra virgin olive oil. Cut half of the lemon
into thin slices and arrange them on top of the fish (keep the other
half of the lemon aside for now). Bake on the middle rack of the heated
oven until the thickest part of the fish flakes easily at the touch of a
fork, for 10 to 15 minutes.
Finish and serve. Remove from the oven and squeeze the remaining lemon all over the fish. Sprinkle on the dill and serve immediately.
Notes
If your halibut fillets come with the skin on, roast them skin side-down. Pull or slice off the skin before serving.