Melt-in-the-middle mozzarella beef burgers

Method

1. Heat a glug of oil in a large frying pan and add the onion. Fry for 5 minutes until starting to soften, then add the garlic. Fry for a further 2-3 minutes, then remove from the frying pan to a plate and leave to cool completely.
2. In a large mixing bowl, mix the beef, cooled onion and garlic, egg, mustard, cayenne and breadcrumbs. Season with salt and pepper, then divide the mixture into 4.
3. Shape each portion into a large patty, place a quarter piece of mozzarella in the centre of each, then form the mix carefully around the mozzarella to encase it fully in a burger shape. Put the burgers on a plate, cover with cling film and chill for 30 minutes. Heat the oven to 200°C/180°C fan/gas 6.
4. Heat a large frying pan with a little oil. When the oil is almost smoking, add the burgers. Fry for 4-5 minutes on each side until the burgers are coloured, then put them in a baking tray. Transfer to the oven and cook for 10 minutes until the beef has cooked through and the mozzarella has melted (test by piercing one carefully with a sharp knife). Leave to rest for 5 minutes, then serve in buns with your choice of toppings and sides.