Steak Sandwich: Place onions, butter and oil in a frying pan. Cook over low heat for 15 minutes, stirring occasionally until soft and lightly golden. Stir in brown sugar, balsamic vinegar and orange juice. Season with Saxa salt and pepper. Continue cooking over low heat for another 10-15 minutes until a rich golden brown. Set aside.
Season schnitzels with Saxa salt and pepper. Spray a frying pan with spray oil. Cook the schnitzel for about 1 minute each side. Set aside, covered in foil to rest.
Toast rolls. Place goat’s cheese on base of each piece of bread, top with spinach leaves, then steak and caramelised onions. Drizzle with remaining Fountain Hickory BBQ sauce. Season with Saxa salt and pepper.
Sweet Potato Chips: Cut sweet potato in half lengthways and then into wedges, line a baking tray with 2 layers of paper towel. Add enough oil to a large saucepan to reach one-third of the way up the side of the pan. Heat to 180 degrees C over medium-high heat (when oil is ready a cube of bread will turn golden brown in 15 seconds).
Add one quarter of the sweet potato to the pan and cook for 1-2 minute or until crisp. Use tongs to transfer to a lined tray. Repeat with the remaining sweet potato, re-heating oil between batches.