PP, if your issue with onions relates to the sulfur compound irritation that Craig is referring to, beyond the steps that Craig suggested, my recommendation is to cook with onions more. If you work with onions at least twice a week, you develop a tolerance for them. In the last five years, I might have shed an onion related tear maybe twice- and on both occasions, I was excited to be crying, because, in my experience, the compounds that produce tears are usually indicative of a more flavorful onion. In the last decade, they've bred a lot of the fierceness out of onions. If you caramelize a lot of onions like I do, an onion that lacks robustness will be almost completely flavorless by the time it's caramelized.