Spray slow cooker with non-stick cooking spray.
Heat 2 tablspoons of olive oil in a large skillet.
Season pork chops with salt and pepper (I omit the salt but add to your personal tastes)
Brown pork chops in a large skillet, about 3-4 minutes per side. Remove from skillet, and place pork chops at the bottom of slow cooker.
Top with the sliced onion.
In a small bowl, whisk together the minced garlic, the maple syrup, Dijon mustard, and apple cider vinegar. Pour on top of pork chops and onions.
Cook on low for 4-6 hours, depending on how thick your pork chops are. Mine took about 4 hours and 20 minutes. Remember, boneless and thinner chops will cook quicker.