A word about using onion powder....learned from Alton Brown of the food channel. He is not only a chef but a food scientist so he knows alot about the properties of ingredients.
When using onion or garlic powder they must be reconstituted for the flavors to be enhanced. I have tried his method and now use much less powder when i do.
If you add the powder to a sauce the sauce and any fat it contains just coats the powder and you need to use a lot.
If you just take the powder, add a little water and make it into first a paste then a slurry and add it to your sauce it becomes much more powerful, hence you need to use less.....give it a try...it works.