1. Preheat the oven to 350°F.
2. In a pan, melt a knob of butter and brown the pork fillet for 2 minutes.
3. Transfer it to a plate and bake for 8 minutes.
4. In the same pan, sauté the onions for 2 minutes.
5. Pour in the whiskey and reduce by half. Add the maple syrup and simmer over low heat for 5 minutes.
6. Bring the milk and broth to a boil. Gradually stir in the cornmeal. Cook over low heat for 20 minutes, stirring constantly. Incorporate the parmesan, butter, and oil. Mix well to obtain a creamy mixture.
7. Transfer the mixture to a greased cake mold. Let it set for 20 minutes and slice it.
8. Using a cookie cutter, cut out 8 circles from the polenta slices. Transfer them to a plate and bake for 10 minutes to dry.
9. Remove the pork fillet from the oven and slice it.
10. Assemble the burgers: a polenta circle, onion jam, two slices of pork, and another piece of polenta.
11. Hold everything together with a wooden stick and serve.