Preheat the oven to 350 degrees F.
Coat the steak brats in the Dijon Cream. Cover the coated brats in the Mushroom Duxelle, and then roll each one in a piece of the flattened puff pastry.
In a bowl, thoroughly beat the egg with the milk to create an egg wash. Brush the egg wash onto the puff pastry. Bake in the oven until golden brown, about 15 minutes. Drizzle the cooked brat in puff pastry with the Bordelaise Sauce. Serve on a plate as a knife-and-fork-dog.
In a medium saucepan, bring the cream to a simmer on medium heat and whisk in the mustard, salt and pepper. Cook until slightly reduced, and then set aside to cool.
In a large saute pan, sweat the shallots and onions in the butter. Add the mushrooms to the saute pan and season with the salt and pepper. Cook until there is no more moisture in the pan.
In a large saucepan over low heat, sweat the garlic and shallots in the olive oil, about 10 minutes. Deglaze with the red wine. Add the Marsala, brown sugar and red wine vinegar, raise the heat to a rolling simmer and reduce the liquid by half, 20 to 25 minutes. Strain the liquid through a fine mesh strainer into a clean saucepan and bring back to a simmer. In a small saucepan, melt the butter, and then add and thoroughly combine the flour to create a roux.
Once the wine sauce has been brought back to a simmer, whisk in the beef base and the roux and reduce by one quarter, 15 to 20 minutes.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.