This a fairly new dip I've introduced my family to and its based on a dip I used to enjoy as a kid in the US
If you want spice it up a tad more then just increase the amount of cayenne
Cut the onion in half and then slice each half into quarters
Warm the oil in the pan anf then add the butter to melt
Add the onions to the frying pan and fry for about 2 minutes on a medium heat
Sprinkle over the Cayenne pepper and sugar and stir in with the onions and fry for another 10 minutes
Turn the heat down and let the onions slowly carmelise for another 20 minutes
Remove from the heat and let cool
Once cool, add the onions to a food processor and blitz to a puree
Add the cream cheese, sour cream and mayo and pulse a few times until mixed and smooth
Decant into a bowl, clink film an place in the fridge
Serve with crudites, salted nachos or pretzels