"These super-juicy mushroom burgers are packed full of big umami flavours," says barbecue aficionado Tom Kerridge. "The dried porcini powder in the butter adds an incredible savoury depth, which is enhanced with chilli, garlic and lemon zest."

Ingredients

Makes 4

  • 2 x 225g packs halloumi
  • 8 portobello mushrooms, stems removed

For the umami butter:

  • 160g butter, softened
  • 2tbsp white miso
  • 1tbsp light soy sauce
  • 5g dried porcini mushrooms, ground to a powder
  • ½tsp dried chilli flakes
  • 2 large garlic cloves, finely grated
  • Finely grated zest of ½ lemon
  • Salt and freshly ground black pepper

To assemble:

  • 4 brioche burger buns, split
  • 4tbsp sweet chilli or hot chilli sauce
  • 4tbsp mayonnaise
  • About 60g rocket leaves

Method

  1. Cut each block of halloumi in half horizontally through the middle to create four flat halloumi steaks in total.
  2. For the umami butter, put all the ingredients into a bowl and mix until evenly combined, seasoning with a good pinch each of salt and pepper.
  3. Brush the portobello mushrooms on one side with the umami butter and place them buttered side down on a medium-hot barbecue. Brush the other side thickly with butter while they are cooking. Turn the mushrooms over after two to three minutes and add the halloumi to the barbecue. Brush the surface of the halloumi with umami butter too. Keep brushing the mushrooms with the butter as they cook; do the same with the halloumi.
  4. Towards the end of the cooking, toast the burger buns on the barbecue. Brush any remaining umami butter onto the toasted buns.
  5. To assemble the burgers, place a mushroom, flat side up, on the base of each burger bun. Top with a halloumi steak and add a spoonful of sweet chilli or hot chilli sauce. Pile a big handful of rocket leaves on top. Spread some mayo on the bun lids and sandwich the burgers together. Tuck in straight away.

Outdoor Cooking: The Ultimate Modern Barbecue Bible by Tom Kerridge, photography by Cristian Barnett is published by Bloomsbury Absolute.