- 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.
- 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.