This salad can be prepared in advance and kept in the fridge. Leftovers can be stored in the fridge for a day or two...the more it rests, the more it gets tasty ;)
Don't be scared by the presence of raw onion...red onions are very sweet. If you find it difficult to digest raw onions (I find it difficult too), add only a few strips to your salad...it will give flavor without being stodgy.