Pour 1/4 cup hot water and the vinegar over dried cherries in a small container. Let mixture stand 10 minutes.
Heat the oil in a small saucepan over medium heat and add onion. Cook until softened and translucent (about 5 minutes or so). Add the cherry mixture, rhubarb and honey, then reduce heat to low and simmer until rhubarb has softened, 8-10 minutes. Grate a pinch of nutmeg into sauce, and season with salt and pepper
Serve over grilled pork chops, or on toast topped with goat cheese.