Heat olive oil in a large frypan over medium-high heat. Season pork chops with salt and pepper and cook in the hot oil until lightly browned on both sides, about 4 minutes per side. Add the wine, orange juice and tarragon then bring to a simmer. Reduce heat to medium-low, cover and simmer, stirring occasionally, 10 to 15 minutes, until the pork is no longer pink in the centre. Remove the pork chops from the frypan, set aside, and keep warm.
Dissolve the cornflour in the water, and stir into the simmering liquid until the sauce thickens, about 45 seconds. Pour sauce over the pork chops to serve.