This is a very simple weeknight dinner that can be done in less than 30 minutes even though the name sounds fancy - the polenta provides a nice and creamy base for the garlic fish. Everything is made on the stovetop to perfection! The secret tip is simply to lightly fry the garlic pieces in the butter before throwing the cod in the pan - you have to watch this part carefully and wait until the garlic turns into a deep brown color, and then you're good to go.