Put flour, salt, pepper and any mild spice in a small paper bag. Melt butter in a large frying pan over medium heat. Place fish cheeks, a few at a time, in the flour bag and shake to coat. Put cheeks into the bubbly butter in the pan and brown until cooked, just a minute or two. Time will vary depending on the size of the pieces. Serve with some of the browned butter poured over and a spritz of lemon.