You can buy dried, minced shallots in the spice aisle. They’re like the freeze-dried astronaut ice cream of the allium world. Rehydrate them in a little warm water or vinegar for 10 minutes before using. They’re not as elegant, but they work in a pinch—literally.
Pro tip: Dried shallots are shelf-stable for years. Buy them once, store them in a dark cabinet, and you’ll never have this panic again. Unless you lose the bag, which you absolutely will.