Method
For the soda baps, pre–heat the oven to 200ºC and lightly oil a baking sheet.
In a mixing bowl, combine together flours and bicarbonate of soda and make a well. Mix buttermilk and egg and whisk to combine together. Pour the mix into the well and mix together with a wooden spoon and until you have a dough.
Form six palm–sized buns, place on a baking sheet and sprinkle with oats. Cook in the oven for 40 minutes. Remove from the oven and set on a wire rack to cool completely.
While the buns are cooking, fry the red onion in a frying pan with a little oil over a medium heat and cook gently for about 8 minutes until soften right down. Set aside to cool completely.
In a mixing bowl, combine the mince, mustard, Worcestershire sauce, egg, breadcrumbs and cooked onion, and season with a little salt and pepper. Form and the meat mix into six burger patties.
Place a frying pan over a high heat and add oil. Fry burgers for 4 to 5 minutes each side until they are cooked all the way through. When you turn the burgers on the pan, add a slice of cheese to each one.
To serve, split the baps and fill with lettuce leaves, slice tomatoes, the burger and a good dollop of garlic sauce.