A slice of onion on a burger gives great taste and texture. There’s a time and place for that kind of burger, and another for a melting oozing mess. This Guinness Onion Jam takes caramelised onions to the next level, providing a malty beer base with sweetness from the onions and sugar.
The jam is good with burgers, especially when paired with a sharp fatty cheese such as a mature cheddar. It’s inspired by recipes for Sticky Onion Marmalade from Riverford and David Lebovitz’s Shallot Marmalade.
All onion recipes are deceptively simple, with a single main ingredient. The secret is patience, taking the time to really caramelise the onions and ensure they almost dissolve in the beer. You can use any dark beer or stout in place of the Guinness.
5 medium onions
Salt – 1tsp
Pepper – 1tsp
Guinness Original – 500 ml
Balsamic Vinegar – 3 tbsp
Golden Caster Sugar – 50g
Mustard Seeds – 1 tbsp
These amounts make just over a single medium 340g jar of the jam, with a little left over for immediate use.
- Evenly slice the onion into rings. Some smaller pieces are fine as these will dissolve more quickly.
- Heat 2 tbsps of vegetable oil in a heavy pan on a medium heat.
- Add the onions and the salt and pepper, stirring to combine and to coat the onions in oil.
- Soften the onions for 15 minutes and then add half of the sugar.
- Continue to soften the onions for around an hour until they are golden in colour and the smaller pieces are falling apart.
- Add the beer and balsamic vinegar.
- Reduce the temperature to a low heat and cover the pan. Let the onions cook for an hour, stirring occasionally.
- Add the mustard seeds, remaining sugar and a splash of water.
- Increase the temperature to a medium heat and reduce until sticky.
If during the process the pan starts to become dry add a splash of water. You don’t want to colour the onions through them burning or sticking, but through a long low heat. You may also need to add a splash of water when adding the second half of the sugar to ensure it coats the onions evenly and that the jam consistency comes together.
I find a heavy cast iron pan is useful for recipes that need a long and slow cook. Cast iron retains heat well and distributes it evenly. I use a Le Creuset pans for cooking on the hob, they’re expensive but will last for so long that the family can fight over them when I’m gone.
* Disclaimer: I may get commissions for purchases made through links on this page. I always try to be clear where I use a specific item, and don’t recommend anything I don’t use myself.