Tangy, stimulating dressing, perfect for a pile of greens.
Add the ginger, onion, and celery to a food processor and pulse that stuff until it's thoroughly combined. Make sure to crape down the sides of the processor with a spatula to get any straggler bits.
Add the soy sauce, lime juice, sugar, ketchup, and pepper the processor. Process everything until it's combined again, 10 to 20 seconds. Finally, while the processor is running, stream the oil into it in a thin stream. Keep processing until well it's blended.