1. Caramelised Onions: Heat butter and oil in a large saucepan over medium heat. Add onions, garlic and thyme. Cover, cook stirring frequently, for 25-30 minutes or until onion is caramelised.  
2. Add sugar. Cook, stirring often, for 10 minutes or until sugar dissolves and coats onion well.  Add red wine, cook out then add balsamic vinegar, reduce to a jam consistency. If dry add a splash of water. Finish with some pan juices, keep warm for service.
3. Dipping Sauce: Heat the roasting pan, add all ingredients and deglaze. Strain and reserve. 
4. Rolls: Lightly regenerate rolls sprayed with a little water in a hot oven for 5 minutes. 
5. Cut and butter each roll.
6. Warm beef in some of the pan juices
7. To finish: Spread roll heel with caramelised onions, followed by beef then cheese. Melt under salamander and garnish with snow pea tendrils, place roll crown on top. Serve with fries and warm dipping sauce in a ramekin on the side.

Chef's notes

• Can use roast beef trim for this recipe.
• Serve with fries or potato crisps as and add on.