Preheat the barbecue to medium or until the charcoal ashes turn white. In the meantime, prepare the bacon and onion jam: in a saucepan, over high heat, drizzle some oil and add the bacon pieces. Cook for 2 minutes until well coloured, add the onions and continue to cook for 5-6 minutes, continuously stirring.
Add the honey, garlic, cider vinegar, white wine and bring to simmer. Drop the heat to low and simmer until the mixture achieves a syrupy texture. Remove from the heat and set aside. Next, flatten the burgers.
Once the ashes on the charcoal barbecue turn white, oil the barbecue ridges, or drizzle some oil on a griddle pan and add the burgers. Cook on each side for 2-4 minutes until cooked through. Add the slices of Gubbeen Farmhouse cheese and allow them to start melting for 30 seconds.
Drizzle the halved brioche buns with oil and toast on the barbecue for a minute. Build your burgers by adding the salad leaves, cooked burgers, bacon and onion jam and gherkins to the brioche buns.