How to chop an onion without having to chase it round the kitchen?!
I was taught how to do this by a chef. To stop it rolling hold it in your hand (or hold on a board) and cut off the top (ie. the end that isn't the root i dont know what its called really) with a sharp knife. The key part is to peel and chop without cutting the root off as this stops it from falling into rings whilst you're cutting it. First chop in two from root to now flat cut-off top. Then with the root furthest away cut slices into it leaving a bit a the root so that it stays in on piece. Then slice it once horizontally parallel to the board halfway up. Finally turn it 90 degrees so the root is on your left (if right handed) and chop, giving you perfectly diced pieces without it falling to bits! hope that helps
Peel the onion and cut it in half. Take one half and cut off the stem end, but leave the root end attached. Cut it in slices lengthwise, but don't cut right through; leave it joined at the end. Then slice it crosswise so you get little bits. I hope that makes sense.
My mum taught me this one.
Hold it firmly and cut it in half. Place the flat side down and continue to slice, each cut will make another flat side, making it so there will be no rolling. Btw, Onion is a stupid name for a dog.
you are making the mistake of not killing it first!! LOL
Luka & Bookworm have already given you the correct answer
Use the Slap Chop:
what you do is cut the onion in half then cut it into slices then continue to chop it up
Go for the legs first, then the rest should be cake.