I have not seen many preparation of raw onions in salads or as sides. The reason I ask is because my mother always had them as sides and I finally asked what she did...
She simply said that she sliced them thinly and let it sit in vinegar for 2-3 hours. Then she washed out the vinegar and finished it with good quality olive oil.
The reason I find it interesting is because onions stay fresh/crispy and become sweeter with little vinegar flavor (nowhere as intense as salad dressings). I find it very good with anything fried or roasted or just in sandwiches/burgers.
Does anyone else do something similar?