In the onion field outside Rimmington.
You can find onions in a bunch of places. Farms can have them, some produce stores have them, a bunch of players may have them, or you can buy them off the Grand Exchange.
Onions can be found in a variety of locations. If you are doing the Witch's Potion quest, there is a field with onions and cabbage just north of Rimmington. Pick one of the nine there. Onions are useful for making dyes as well as completing the quest.
At lumbridge where the chicken house is go to the back of that house and you will find onion plants pick the onions you can pick as many as you want feel free to leave comments .
RuneScape's website and the website of the creators of RuneScape can be found in the related links section.
Gluten is found in wheat, not onions or any other vegetables.
You can pick them from behind Farmer Fred's farm, just follow the road North from Lumbridge Castle.
In the patch behind Fred the farmer's farmhouse. also in the patch by Melzar's maze
you can pick them at some farms like out the back of Fred the farmers one near lumbridge or if you are a member you can grow your own
granite can be minned via the desert. here's a guide i found on runescape:
Approximately 70-90 Spanish onions are typically found in a 50 lb bag, depending on the size of the individual onions.
The acid found in onions is called sulfuric acid.
Felidip hills