Stuffed onions?

I have heard of them. Does anyone regularly do this! And what do you stuff 'em with!

saw Jamie oliver do this the other night. Think he just cut a cross in to red onions and stuffed with herb butter

Here's another of Jamie Olivers stuffed onions, which is really good!
Roasted Stuffed Onions - the Naked Chef, Jamie Oliver
4 white onions (tennis ball size white onions peeled)
olive oil
2 garlic cloves (peeled and finely chopped)
4 sprigs fresh rosemary (lower leaves picked)
8 tbsps heavy cream
2 cups freshly grated parmesan (cheese approximately 2 handfuls)
salt
pepper
4 slices bacon (smoked)
Boil the onions in plenty of water for 15 minutes, until slightly tender. Remove from the pan and allow to cool. Remove the top 1 inch of each onion and reserve. If need be, slightly trim the stalk end of the onion so that they sit flat on a roasting tray.Cut about a heaped tbsp out from the inside of each onion, keeping the outside intact. Finely chop along with the reserved onion top.
Pre heat the oven to 400°F.Heat a frying pan and add a little olive oil, garlic, chopped onions and a little chopped rosemary. Fry for a couple of minutes then turn the heat down and add the cream. Remove from heat and stir in the parmesan and season to taste. Wrap a rasher of bacon around each onion and secure with the sharpened rosemary twig or half a cocktail stick.Place the onions on the roasting tray and spoon some of the filling inside each one. Bake for 25 minutes. Place the onions on a warmed serving plate, warm through any remaining filling and serve on the side.

Unusual.
Sounds like a recipe from Come Dine With Me