Step 1

Place all the duxelles ingredients into a food processor. Process until small pieces (do not puree). The goal is to achieve a finely chopped texture, not puree the mushrooms.

Step 2

Lightly grease a skillet with butter. Add the duxelles and sauté until lightly browned and most of the water has evaporated. Set aside.

Step 3

Lay a sheet of wide parchment or plastic wrap out on the counter. Place 4 or 5 slices of prosciutto, long sides overlapped by ½-inch or so, on the plastic wrap.

Step 4

Spread the duxelles over the center of the prosciutto. Set aside.

Step 5

Preheat a skillet over medium-high heat. Melt the butter then brown just the outside of the meat on all sides, including the top and bottom. Transfer to a plate. While the meat is still hot, brush it all over with the dijon mustard.

Step 6

Place the meat on top of the duxelles, towards one end of the rectangle.

Step 7

Roll the whole thing up using the parchment or plastic wrap to assist. Twist the ends of the plastic wrap tightly so that the Wellington looks shaped like a candy roll.

Step 8

To make the carnivore pastry dough, place the mozzarella and the butter in a heat safe bowl and microwave for 1-2 minutes or until the cheese is entirely melted. Stir well.

Step 9

Roll the dough flat between two pieces of parchment paper.

Step 10

Place the prosciutto-wrapped beef in the middle and wrap the dough around the meat, sealing the edges.

Step 11

Flip the whole thing over so that edges/seams are at the bottom. Brush with a beaten egg yolk.

Step 12

Bake for 45 minutes in a 425 degree F oven (tent with foil if the pastry is getting too brown after 20 minutes). Allow to rest for 10 minutes before cutting.