1. Center a rack in oven and heat to 400 degrees.
2. Combine 1 3/4 cups stock and the quinoa in a medium saucepan and bring to a boil over medium-high heat. Add thyme, cover, and reduce heat to medium-low. Simmer until liquid is mostly absorbed, about 15 minutes; remove from heat and let sit, covered, 10 minutes. Discard thyme sprigs, fluff with a fork, and cover to keep warm.
3. Meanwhile, whisk mustard and remaining 3/4 cup stock in a small bowl; set aside. Rub pork all over with maple-sage seasoning and season lightly with salt and pepper.
4. Heat oil in a large oven-safe skillet over medium-high heat until just smoking. Add pork and cook, turning occasionally, until browned all over, 5 to 7 minutes; transfer to a plate. Add apples and onion to now-empty skillet, season with salt and pepper, and cook, stirring frequently, until browned and just tender, 6 to 8 minutes. Carefully add stock mixture (it will bubble), scraping browned bits from bottom, and cook until slightly thickened, about 30 seconds.
5. Return pork to skillet and transfer to oven. Roast until thickest part of pork registers 145 degrees, 15 to 20 minutes. Let rest 5 minutes, then slice and serve with quinoa, apples, and onions.
Source: Hannaford fresh Magazine, December 2019