In a gallon size sealable freezer bag, add the sugar, salt, garlic and water. Seal the bag and swish it around to dissolve the sugar and salt. Add the pork, press out as much air as you can, then seal the bag. Let this sit in the refrigerator for at least 4 hours, or preferably overnight.
Remove the pork chops from the brine and use paper towels to remove as much moisture from the surface of the pork chops as you can. If there's water on the surface of the pork chops, they will not brown.
Add the oil to the pan and heat over medium high heat. Place the pork chops in the pan while the pan is still cold. Because the pork chops are brined with sugar, they'll burn before they cook through if you put them into a hot pan.
Fry the pork chops undisturbed until they are golden brown on one side and have gone from pink to beige about halfway up the sides.
Flip the pork chops over and fry the second side until well browned and an instant read thermometer reads 141 degrees F (60.5 C). Transfer them to a plate and let them rest.
Drain the excess oil out of the pan, and then add the onions and garlic. Sauté until the onions are soft.
Add the wine, honey and mustard and then turn up the heat to boil off the alcohol and thicken the glaze.
When the glaze is nice and thick, add the pork chops back to the pan and flip them over repeatedly to coat them with the glaze. Once there is no liquid left in the pan, the pork chops are done. Top with the caramelized onions and and serve with mashed potatoes.