Came across this recipe while I was cruising the net. I made this first before I posted it. Wanted to make sure what they tasted like. They were great. This is from a British site. I can't wait till this fall to make these again.
Sprinkle the salt over the dry, peeled onions, stir to make sure the salt is distrubuted and leave overnight. Next day (do not leave longer than overnight if you want your onions to be crisp) rinse the onions and dry with a kitchen towel.
Place the spices, vinegar and sugar into a large stainless steel pan. Heat and disolve the sugar but do not boil.
Pack the onions into clean, sterilized jars. Pour over the vinegar and spice liquid to fill the jars, make sure each jar has pickeing spice in and check there are no air pockets. Seal the jars and leave to cool. I used 1/4" of head space.
The onions will be ready to eat after about a month or better if kept two.
NOTE: Peeling pickling onions is fiddly and time consuming. To speed up the process top and tale the onion, then place the onions a large heatproof bowl and pour over boiling water to cover. Leave to cool, and once the water is cool, hey presto, the skins will just rub away. Drain and pat onions dry. Do not leave in the water once cooled or the onions will start to go mushey.
NOTE: If you don't have pickeling spice you can use 1/2 tsp coriander, 1/2 tsp mustard seed, 1/2 tsp black peppercorn, 1/2 tsp dried chili flakes.