Quarter the red potatoes, and chunk the onion. Put in large baking dish and drizzle olive oil on top. season with kosher salt and fresh ground pepper. Put in 425°F oven. Stir veggies every 15 mins.

Combine mustard, minced garlic, and thyme leaves. One side of the pork loin should have a layer of fat. Coat this side with a thick layer of the mustard mixture. Leave on countertop in room temperature for 30 mins, while veggies are roasting.

When the veggies are starting to brown, make a bit of a well in the center, and add the roast. After twenty minutes, check the temp of the roast, in the center. When it has reached 138°F, try to catch this as close as possible, remove the roast but leave the veggies in the oven. Allow the roast to rest again, with a tent of aluminum foil over it, for 15 minutes. Remove the veggies from the oven and serve with sliced pork roast. This makes the most tender pork roast of any recipe i have tried.