Lay 3 grape leaves on the counter with the stem ends intersecting to form a triangle. Sprinkle one quarter of the mint and one quarter of the oregano in the middle of the triangle. Season the fish with salt and pepper
and lay on top of the herbs. Lay 2 lemon slices on top of the fish and fold the grape leaves as you would an envelope. Repeat with the remaining fish.
Set the fish in the steamer basket and steam 5 to 7 minutes, until the fish is firm to the touch.