In a large pot, heat up a water bath to 165° F
Trim the extra fat from the pork loin, and place in the bag.
Generously season with salt and pepper. Add in the smoked paprika, cumin and instant coffee.
Cut one of the onions in half and add to the bag with the carrots, 3 of the garlic cloves and 1/2 cup of red wine.
Press out all the air from the bag, seal and drop into the water bath. (If there is air left in the bag, it will open.)
Set the sous vide circulator to 4 hours, cover the water bath with a layer of plastic wrap and, over that, aluminum foil.
When the pork is ready, remove from the bag and cover to keep warm. Melt the butter in a medium sauce pan, add in the sauce and vegetables from the bag along with any pork fat. Chop the rest of the onions and garlic, and add those in as well. Sauté until the onions get a bit of color, about 5 minutes.
Transfer the sauce to a bowl, add in 1 cup of red wine, and using an immersion blender, blend until smooth. Strain through a fine mesh sieve into a medium-sized pot. Discard the remnants left in the sieve. Bring the sauce to a boil. Check the seasoning and adjust as needed.
Slice the pork into 3/4 to 1 inch slices. Add the slices to a medium-sized pan and, over medium-low heat, drizzle 2 tablespoons of sauce per slice. When the meat absorbs the sauce, flip the slices and repeat with 3 tablespoons of sauce per slice.
Plate immediately and serve with more sauce.