Heat the olive oil in a large skillet over medium-high heat.
Season the boneless pork chops lightly on both sides with salt and black pepper.
Place the pork chops in the hot skillet and sear on both sides until browned. The pork chops should not be fully cooked at this stage. Remove them from the skillet and set aside.
Chop the potatoes into evenly sized pieces and place them in the bottom of the slow cooker.
If using carrots and celery, chop them into similar-sized pieces and add them to the slow cooker with the potatoes.
Pour the cream of chicken soup and chicken stock over the potatoes and optional vegetables.
Add the thyme, parsley, granulated onion, granulated garlic, celery seed, salt, and black pepper. Stir gently until the potatoes and vegetables are coated with the soup mixture and seasonings.
Place the seared pork chops on top of the potato mixture in the slow cooker.
Cover the slow cooker with the lid. Cook on high for 3 to 4 hours, or on low for 6 to 8 hours, until the pork chops are fully cooked and the potatoes are tender.
If a thicker sauce is desired, remove a small amount of hot liquid from the slow cooker 30 minutes before the cooking time is complete. Mix the liquid with 2 tsp cornstarch until smooth.
Stir the cornstarch mixture back into the slow cooker. Cover and continue cooking for the remaining 30 minutes, or until the sauce has thickened.
Serve the pork chops warm with the potatoes, vegetables, and sauce spooned over the top.