To making the patties, after pouring the mixture on the tray with parchment paper, flatten the mixture using a spatula and form a square shape using the edges of parchment paper lift the edges up and fold to cover the mixture with the paper. Set aside and let it completely cool and stabilize.
After it cools and get hard, choose a baking ring or round shaped cutter to make round patties. I chose a small round shape.
With your finger gently press the pattie to pull it of the ring. Set a side and repeat this action for the next patties.
Now you can choose to either bake it or pan fry it, if you like to bake the patties, place on a baking tray with baking paper and bake in a pre-heated oven at a 180°C/350°F for about 20 minutes or until golden brown.
if you want to pan fry it you can heat some grape seed oil or vegetable oil on medium high heat and place each pattie gently in the pan, flip gently when golden brown on one side and when ready place in a plate with paper towel to absorb the oil.
Take a serving plate and place the pattie in the middle. With the baking ring you shaped the polenta , gently place it on top of the pattie to shape the Duxelles mixture on the pattie in an even way. Scoop 2 or 3 TBSP of Duxelles on the pattie and press gently while holding the ring.
Serve with the toppings you like see options below.