Preheat oven to 250 degrees F (120 degrees C).
Heat Olive Oil (3 tablespoon) in a large heavy skillet over medium-high heat. Season Boneless Beef Short Ribs (3 pound) on all sides with Salt and Pepper (to taste). Working in batches, sear short ribs on all sides until deeply and evenly browned, 2 to 3 minutes per edge.
Remove ribs from pan and place in a dutch oven or roasting pan. Leave the oil in the skillet.
Over medium-low heat, saute the Smoked Bacon (4 slice) until lightly crispy. Scoop bacon out into the short rib pan. Return skillet, with some oil still in it, to the stovetop.
Increase heat to medium-high and add Yellow Onion (1), Carrot (2), and Celery (2 stalk) sauteéing and stirring occasionally until lightly caramelized.
Add Garlic (6 clove) and sauté for 1 more minute.
Add Tomato Paste (4 ounce) to the softened vegetables and stir frequently for 2 to 3 minutes.
Add Red Wine (2 cup); heat to a simmer and continue cooking, stirring occasionally, until the liquid has reduced by half.
Add Beef Stock (2 quart), Fresh Rosemary (1 sprig), and Fresh Thyme (1 sprig) and heat to boiling. Remove skillet from heat.
Pour vegetables and liquid over the short ribs and bacon in the Dutch oven or roasting pan. Short ribs must be completely submerged in liquid. Cover pan with lid, or aluminum foil. Roast in the oven 2 1/2 to 3 hours until beef is very tender but still holds its shape.
Remove from oven and cool for an hour at room temperature.
Remove meat from pan and place on a cutting board. Pour everything else into a large colander, capturing all of the braising liquid. Set the braising liquid aside. Discard the vegetables.
Strain the braising liquid through a mesh strainer into a large heavy skillet.
Heat the reserved braising liquid over medium-high heat and simmer until liquid is reduced by half. While the braising liquid reduces, cut meat into bite-sized pieces. Place sliced meat and reduced braising liquid in a covered container and refrigerate overnight.
In a large, heavy skillet over medium-low heat, cook Smoked Bacon (0.5 pound) until lightly crispy. Remove bacon and reserve; leave rendered fat in pan.
Saute Yellow Onion (1) in the bacon fat until lightly caramelized, about 15 minutes.
Add Mushroom (1 pound) and sauté 3 to 4 minutes, stirring occasionally. The mushrooms will release their moisture during this quick sauté.
Add Garlic (6 clove) and sauté for 1 minute.
Add Dry Sherry (1 cup) and deglaze pan; reduce liquid by half.
Add reserved the braised short ribs and cooked bacon pieces, Stone Ground Mustard (3 tablespoon), Fresh Thyme Leaves (1 tablespoon), and Fresh Rosemary (2 tablespoon).
Add the reserved reduced braising liquid. Over low heat, warm the mixture until simmering. Allow to reduce and thicken. Season to taste with Salt and Pepper (to taste).
Prepare Pappardelle Pasta (1 package) according to package instructions. Butter (2 tablespoon) noodles and divide into individual serving dishes or onto serving platter.
Whisk Crème Fraîche (6 ounce) with White Truffle Oil (2 tablespoon).
To serve, ladle meat/mushroom sauce over buttered pappardelle noodles, garnish with dollop of creme fraiche and sprinkle with Fresh Parsley (1/4 cup). Serve immediately.