Start by melting your butter in a pan, then add in your chicken stock and whole milk. Then, go in with your polenta and stir well. Note that this dish is one that requires constant stirring.
Season with salt and onion powder and continue to stir as it begins to boil. Once boiled, reduce the heat to medium-low as it thickens up.
Add in your heavy cream and parmesan. Stir in well. You may need to add slightly more heavy cream to achieve the correct consistency. Just before finishing, add in your cheddar and incorporate well. Serve with a braised beef dish.