Pat the pork chops dry with paper towels. Season both sides with salt and pepper.
Heat the olive oil in a large skillet over medium-high heat. Add the pork chops and sear for 3-5 minutes per side, until golden brown. (They don't have to be cooked through at this point.) Remove the pork chops from the skillet and place them in a Crock Pot.
In the same skillet, add the sliced onion and cook for about 5 minutes, until it begins to soften, stirring occasionally.
Add the minced garlic to the skillet and cook for 1 minute, until fragrant.
Sprinkle the arrowroot powder over the onions and garlic, stir to combine, and cook for 1 minute, until the arrowroot powder is well incorporated.
Slowly whisk in the chicken broth. Bring the mixture to a simmer and cook for 2-3 minutes, until thickened slightly.
Stir in the Worcestershire sauce, Dijon mustard, thyme, and rosemary.
Pour the gravy over the pork chops in the Crock Pot.
Cover and cook until the pork chops are tender:* Bone-in pork chops: 5-6 hours on Low or 2-3 hours on High.* Boneless pork chops: 3-4 hours on Low or 1-2 hours on High.
