Preheat the oven to 400 degrees.
Put flake salt on both sides of the fish and also inside the fish. Salt to taste! Remember, you can always add salt once it is almost all the way cooked, and this kind of fish can take a lot of salt
Squeeze 1-1/2 lemons on each fish, half a lemon per side and inside.
Make three slits on top of the fish in a diagonal design.** Tip: make the slits from the base of the knife up.
Insert a piece of garlic into the diagonal slits using all 6 slices of garlic.
Insert 3 sprigs of rosemary diagonal inside each fish.
Cook fish uncovered in a 400-degree oven for 20 minutes. Then, turn the broiler on high or 450 degrees and broil for another 5 minutes or until golden brown and crispy skin.