This recipe uses leftover Bolognese meat sauce and chilled polenta. The prep time is for making the béchamel sauce and building the layers in the baking dish.
Preheat the oven to 450°.
Prepare the béchamel sauce to the consistency of sour cream.
Warm the bolognese sauce on the stove so it will spread easily in the dish.
Slice the chilled polenta into layers about ½" thick.
Butter a deep baking dish and place one layer of sliced polenta on the bottom. Patch gaps with additional polenta, where needed.
Add a layer of bolognese sauce. Drizzle a layer of béchamel sauce and sprinkle a thin layer of Parmesan cheese.
Repeat until you have used all of the ingredients, or until you reach the top of the baking pan. Sprinkle a final layer of Parmesan and dot sparingly with butter.
Place in the oven for 15-20 minutes. I recommend placing the dish on a baking sheet in the over, in case liquid spills over the top.
When a light brown crust has formed, remove it from the oven.
Let it rest for 5 minutes before cutting and serving.
When preparing leftovers, cut into slices and store.