Red Onion and Chive Beef Burger in Portobello ‘Buns’

Prep time: 15 minutes
Cooking time: 15 minutes
Serves: 4
Served with peppery rocket leaves


  • 8 portobello mushrooms, stalks removed
  • 600g beef mince
  • 4 tbsp chopped chives
  • 1 egg, lightly beaten
  • 30g breadcrumbs
  • 1 red onion, finely sliced
  • 1 cucumber, deseeded and thinly sliced lengthwise
  • 25g sugar
  • 20g salt
  • 75ml vinegar
  • 25ml water
  • Rocket leaves to serve
  • Olive oil
  • Salt and pepper to season


  1. Put the beef, chives, egg, onion, breadcrumbs and a pinch of salt and pepper in a mixing bowl. Mix well with your hands then divide into four and shape into burgers. Put on a plate and put in the fridge to chill for about half an hour.
  2. Put the sliced cucumber in a glass bowl. Heat the sugar, water, salt and vinegar in a pan until dissolved then leave to cool before pouring over the cucumber. Leave to pickle for about 20 minutes.
  3. Season and char the outside of each mushroom on a skillet or barbecue then set aside. Cook the burgers to your liking on the chargrill.
  4. Drain the cucumbers from the pickling liquid.
  5. Put a burger on top of a mushroom ‘bun’, add a little pickled cucumber and a handful of rocket. Put the top of the ‘bun’ on and serve with ketchup and mustard.