Sprinkle pork on all sides lightly with kosher salt. In a small bowl combine the garlic powder, thyme and black pepper. Rub the seasoning over all sides of the loin.
In a skillet heat the oil and brown the loin on all sides. Transfer the loin to a crockpot. Combine the broth, lemon juice and soy sauce and add to the crockpot.
Cover and cook on LOW for 8-10 hours or HIGH for 4-5 hours.
After cooking transfer pork loin to a platter and cover to keep warm.
To make gravy, pour the drippings from crockpot into a measuring cup. Skim off the fat. Measure two cups of drippings (adding water if needed). Pour 1 1/2 cups of the drippings into a saucepan. Heat over medium-high heat until hot.
Whisk cornstarch into the reserved 1/2 cup liquid and whisk into hot drippings in saucepan. Heat until thickened and bubbly. Season with salt and pepper, if desired. Serve with roast.
