Start by finely chopping your mushrooms, shallot, and grate your garlic. A food processor also works great for this.
Add 2 Tbsp of butter to a pan over medium heat. Add in you mushrooms, shallot, garlic, and thyme. Also add a pinch of salt and pepper.
Cook until the mushrooms have released all of their liquid and they begin to look slightly dry.
Using a bowl or cup, cut out a circle with the ouff pastry to act as our beef wellington bun. Place them on a sheet tray and brush with egg wash. Bake them similar to the package directions, but keep an eye on them throughout the cook.
Season your filet with Crove Food Co. Beef Rub & Seasoning. Add a Tbsp of oil to a skillet and place over high heat. Add your filet and cook for 2-3 minutes and flip. Once you have flipped, add in 2 tbsp of butter, a clove of crushed garlic, and another sprig of thyme. Baste until it has reached your desired doneness.
Once removed, optionally add in your prosciutto for 1-2 minutes per side.
Combine all of the ingredients for the horseradish sauce.
All that is left is to assemble your burger as you please. We started with a layer of the sauce, then the duxelle, then the prosciutto, then the filet, and then more sauce and the top bun!