I've never seen packaged caramelized onions; I'm not sure how you could package them and have them taste even remotely nice. Do you mean onion jam? That's a rather more normal thing to serve with cheese and crackers and that you might buy pre-prepared, I think.
If you can find the Beekman Boys 1802 blaak onion jam it's amazing. Not sure if it's available locally, but I've bought it in the usa.
shop.beekman1802.com/
Stuart S they practically own Sharon Springs, NY; and I think their operation is worth WAY more than what they won on TV. They had their own TV series in the states before they went on AR and used to be regulars on Martha Stewart. They make beautiful goat's milk soap too...
I believe I've seen the roasted garlic onion jam at Saslove's and Brian's Butchery. There are probably other places, too, but I just don't know about 'em.
RiceLover