PREPARATION
Beef Patty
- Mix all the seasonings into the lean mince until just combined.
 - Divide the mince into 4 portions, each about 160g. Roll into balls, flatten into patties and press a dent into the centre of each patty using the thumb. This prevents the patty from forming a dome and shrinking when cooking.
 - Cover and chill the patties until ready to use.
 
Sauteed onion and portobello mushroom in teriyaki sauce
- In a frying pan, heat 1 tbsp of olive oil, add onion and sauté till slightly softened.
 - Add sliced mushroom and sauté till softened.
 - Combine the teriyaki sauce ingredients except corn starch and water, and add the sauce to the onion and mushroom.
 - Stir-fry sauce with onion and mushroom till fully cooked.
 - Mix corn starch and water and add the mixture into the frying pan.
 - Stir till sauce thickens slightly. Dish and set aside.
 
Assemble
- In a frying pan, heat 2 tbsp of olive oil, add the beef patties and cook for 4-5 mins on one side.
 - Flip to the other side and cook for another 1 min.
 - Add 1 slice of cheese to each beef patty, cover and cook for another 30secs.
 - Remove beef patties from pan onto a plate and let them rest.
 - Slice the burger buns into halves, butter on both sides and toast till slightly browned.
 - Squeeze 1-2 tsp of mayonnaise on the bottom half of the bun. Add a piece of lettuce, followed by tomato, beef patty and lastly onion and mushroom. Close with top half of the bun. Use a bamboo skewer to hold the burger in place if necessary. Repeat for the remaining burgers.
 - Serve warm.
 
              
                  

