Season the pork loin with salt, and in a small bowl combine the garlic powder, ginger, dried thyme, and black pepper.
Rub the seasoning over the surface of the pork loin.
In a skillet heat the oil and brown the pork loin on all sides.
Transfer the pork to the crock pot.
Combine the chicken broth, lemon juice, and soy sauce; pour over the pork loin.
Cover and cook on low heat for 8 to 10 hours or on high or 4 to 5 hours on high.
Transfer the roast to a platter to keep warm and the drippings into a saucepan.
Stir the cornstarch into 1/2 cup of the drippings, then stir into the liquid in the sauce pan.
Heat, stirring frequently, until the gravy is thick.
Taste and season with salt and pepper, if needed.
Serve the roast with the gravy.