Maybe too late for your urgent cooking, but if not:
1) other alternatives...a little bit of garlic or leek
2) if only a small amount of onion powder required, you may make the dish without it
3) if you want a sharp or umami flavor to replace it, consider mushroom, mustard, hot pepper, horseradish, soy sauce, miso...
What are you making? A small amount of fresh onion or scallions can provide the same flavor. Onion salt if you have it, then adjust the salt in the recipe.
2 Comments
1) other alternatives...a little bit of garlic or leek
2) if only a small amount of onion powder required, you may make the dish without it
3) if you want a sharp or umami flavor to replace it, consider mushroom, mustard, hot pepper, horseradish, soy sauce, miso...