the ultimate organic onion is the Ramp, and this weekend there are numerous ramp festivals in the Carolinas and East Tennessee. They are so strong when cooked or fried, that my mom would make us change our clothes outside and often burn them to get rid of the smell, it is that pungent.
I like them fried, in a spot of bacon grease, and with scrambled eggs. I have eaten them raw like you would a regular green onion, but one needs to be prepared. It is not a taste like any other I have had. They can be really great in stews, especially game meats or root vegetable based, like rutabaga or potatoes in a dark, hearty soup. If you get the chance to try them, it is limited experience, as many never get the chance.
Look for a ramp festival near you. Onions are mellow by comparison.