Sprinkle both sides of the pork medallions with salt and pepper.
Heat a lidded sauté pan over medium-high heat. Add one tablespoon of neutral vegetable oil to the pan.
Sear the medallions in the oil until nicely browned on each side, about 3 minutes per side.
Add chicken or vegetable stock, jam, mustard, ginger, and vinegar to the pan. Bring to a simmer, cover, and simmer over low heat until the internal temperature of the pork is 155-157 degrees F, about 15-20 minutes, depending on your stove.
Remove the pork to a platter and cover with foil.
Return the pan to the heat, and turn the heat up to medium-high. Bring to a boil and reduce the sauce until thick and syrupy. Taste and adjust seasonings, if necessary.
Remove from the heat and swirl in the butter, just until melted. This will enrich the sauce and give it a nice sheen.
Plate the pork and spoon the glaze over the medallions. You may serve this along with the Pear, Walnut and Goat Cheese Salad. The two will complement each other nicely.