There is nothing wrong with doing a pork loin in the crockpot. You could do this one in it--it is a braise. I have totally given up on pork loins
for roasting. they are just too lean and if you even slightly overcook them with dry heat they are tasteless and dry. Try this braise. It is absolutely delicious.
Braised Pork Loin with Apples and Onions
2 lbs center cut pork loin, trimmed to remove any excess fat and silver skin
Salt and freshly ground black pepper
1/2 tsp ground sage or poultry seasoning (I used poultry seasoning)
2 tsp grape seed oil (this was used because of its high smoke point, and also to reduce the "bad" fat)
2 large sweet yellow onions (Vidalia, 1015, etc)
peeled, halved, and thinly sliced
1 cup of dried apple slices, halved (try to get unsulfered, if available)
2 cups chicken stock (I use Swanson or Pacific, low fat)
1 large can frozen apple juice concentrate, thawed
4 Granny Smith apples, peeled, cored, and sliced 1/4" to 1/2" thick
Preheat the oven to 350 degrees. Adjust the rack to the lowest position. Season the pork all over liberally with salt, ground pepper, and sage or poultry seasoning. Heat a large stewpot that has a tight-fitting lid, on high heat. (I used a Le Creuset pan, which worked quite well.)
When hot, add the oil and brown the pork loin in the oil, all over, until deep golden brown. Remove the roast from the pot and set aside. Reduce heat to medium.
Add onions to the pot and cook them, stirring occasionally, until they begin to caramelize and turn brown, about 8 minutes. Add the dried apples, chicken stock, and apple juice concentrate to the onions in the pot and stir. Put the pork roast back in the pot and bring the pot to boil on the stovetop. Put the lid on the pot and put the pot in the preheated oven. Cook pork, covered, for approximately 1 hour. (I found this cooking time to be much too long...check at about 30 minutes).
Remove the cover from the pot and add the Granny Smith apples and stir. Baste the roast with the pan juices. Return the pot to the oven, uncovered, and cook 1 hour more, basting occasionally with the pan juices (again, I think this cooking time was too long; you don't want to overcook the pork until it dries out.)
Remove pot from the oven.
If the sauce seems too watery, place the pork on a cutting board and cover with a loose foil tent, and place the pot back on the stove on high heat and boil the juices down until they are syrupy, stirring as necessary so the apples and onions don't stick. Omit this step if there is little liquid in the pot. (I didn't find this step necessary.)
Taste sauce and correct seasonings if needed.
Slice pork and place it on a serving platter, surrounded with apples and onions and drizzled with pan juices.