Method Prep:30min › Cook:20min › Extra time:30min › Ready in:1hr20min
Preheat oven to gas 6 (190 degrees C).
Put a tablespoon of olive oil in the frying pan. Then you fry the onion on a low heat for 8-10 mins, stirring frequently. Stir in dried mixed herbs and soy sauce. Leave to cool for 10 mins.
Break the egg into a large bowl; whisk with a fork. Add the beef, breadcrumbs, cooked onions and a pinch of salt and pepper. Mix well.
Divide the mixture into four even sized burgers. Wipe a baking tray with olive oil, then place burgers on the tray; cook in the oven for 10 mins. Turn them over and cook for another 10 mins. To check burgers are cooked through, push a knife into them and press top, the juices should be clear, not pink.
To make the tomato salsa: Place the chopped tomatoes in a bowl; add chopped red onion, freshly chopped coriander, olive oil, balsamic vinegar and a pinch of salt. Stir well to combine.