Roasted Pork Tenderloin with Apples and Onions

This is an excellent low calorie meal that still feels filling and satisfying. The key is layering flavors without adding fat. Pork tenderloin (not pork loin) is very low in fat.
Salt and pepper the tenderloin and rub with a little sage. Sear it in a cast iron skillet over high heat with just a little olive oil. Remove meat from the pan and pour in 1/4 of a cup of chicken stock and scrape up any browned bits. Remove from heat. Add to pan one coarsely chopped apple and 1/2 of an onion and place tenderloin on top. Place in a 350 degree oven. Start checking after 30 minutes with a meat thermometer. You want it to just hit 160 degrees internal temperature. Meanwhile, peel and slice 2-3 apples and one medium onion and spread them out on a sheet pan. Salt and pepper and add some sage and a couple teaspoons of olive oil and toss to coat. Place in oven with the tenderloin. After 15 minutes or so stir the apples and onions around and put them back in until they are browned.
I served this with sweet potato spears. Cut a sweet potato lenghtwise. Coat a sheet pan with a very thin layer of olive oil and arange sweet potatoes so a cut side is down on the pan and put in oven. After 30 minutes flip the potatoes over and put back in oven for approxamitely another 30 minutes.
When the tenderloin is finished cooking remove it from the pan. Discard the apples and onions from the tenderloin pan. Place pan over medium heat on stove and pour in two cups of low fat or no fat chicken broth and stir to lift any sticky bits from the bottom of the pan. Let this reduce until slightly sticky and thick and season to taste. Slice tenderloin on an angle. Arrange browned apple and onion slices over the top of the meat and pour a small amount of sauce over top.