Preheat the oven to 400 degrees F.
Place each pork loin between 2 pieces of plastic wrap
. With a beef mallet, lightly pound out the pork loin, very thin 1/6 to 1/8-inch thick. Unwrap the pork loin and season both sides with salt and pepper. Lay three slices of the bacon on a flat surface. Place the pork on top of the bacon along one end. Spread 1/4 cup of the duxelle over the top of each pork loin
. Divide the avocado slices into fourths and lay the slices on top of the duxelle.
Gently roll up each pork with the bacon. Place the roulades on a baking sheet, seam side down, lined with parchment paper, and roast
until the bacon is brown and crisp
and the pork meat is tender, for about 30 minutes. Remove from the oven and allow the roulades to rest for 5 minutes, before slicing. Using a very sharp knife, trim off the ends of each roulade
and cut each across into 4 slices. In a sauce
the chopped bacon, until crispy for about 8 minutes. Add the shallots, garlic, and Armagnac and cook for 1 minute. Stir in the demi-glace
, salt and pepper. Bring the liquid to a boil and reduce to a simmer
. Cook for 20 minutes. Whisk
in the butter and remove from the heat and serve with the roulades. To assemble, spoon 1/4 cup of the sauce on each of 4 plates and arrange 4 roulades slices on top.