Cut the plums in half, lengthwise, gently remove the pits, and then cut each half horizontally into thin slices. (They can be cut in half much like an avocado: Slice around the pit, and then gently twist the halves to pull them apart.)
Arrange the plum slices evenly between two dessert plates, in a circular pattern, or however you’d like.
Remove the stems from the strawberries, cut them into thin slices, and arrange them any which way on top of the plums.
Add the balsamic vinegar to a small saucepan and place it over high heat. As soon as it’s bubbling, turn the heat to low and simmer just until it becomes thick and is reduced by about half, about 7 minutes.
Add a scoop of the ice cream on top of each plate, drizzle with the balsamic glaze, and sprinkle with a bit of freshly ground black pepper.
Garnish with a few sprigs of fresh herbs if desired, and serve immediately!