1Pull the pork loin out of the fridge 30 minutes before cooking and pat it dry with paper towels. Heat the oven to 425°F with a rack in the middle. Set a wire rack inside a roasting pan.
2Stir the dijon mustard, brown sugar, garlic, smoked paprika, kosher salt, black pepper, dried thyme and onion powder into a thick paste.
3Rub the paste over the top and sides of the pork loin in an even layer.
4Lay the bacon slices side by side across the loin, slightly overlapping, and tuck the ends underneath. Cut 5 or 6 pieces of kitchen twine, slide them under the roast, and tie loosely around the loin at even intervals so the bacon stays in place.
5Set the roast seam-side down on the rack. Roast at 425°F for 20 minutes to start the bacon browning.
6Lower the oven to 350°F and keep roasting for 40 to 50 minutes more, until a thermometer in the thickest part of the pork reads 140°F.
7If the bacon is not as crisp as you like, switch the oven to broil and cook 2 to 3 minutes, watching closely, until deep golden.
8Move the roast to a cutting board and rest it for 15 minutes. The temperature will climb to 145°F as it rests and the juices will settle.
9Snip the twine and discard every piece. Carve the loin into slices about 3/4 inch thick, keeping a strip of bacon with each slice. Spoon any pan juices over the top.