I'm going to need more information on "stewed onions". Nevah hoid of such a thing.
and onion salt ... what's that?
You can just stew (cook in boiling water) or steam onions until tender as you would any vegetable. Salt, pepper or use other seasoning to taste. I especially enjoy whole or half peeled onions dropped in with the pot roast for the last 20-30 minutes. Makes the roast yummier and the onions yummy too.
Onion salt is called Onion Salt and is a bottled seasoning (onion powder and salt) you usually can find in the spices section of the grocery store along with salt, pepper, garlic salt, celery salt etc. You can use it for all sorts of things but I use it mostly for the friend potato/onion stuff I described. Onion salt is the only seasoning I add and it is plenty.