• Heat a lightly oiled griddle or frying pan over a medium-low heat for 1-2 minutes. Coat the mushrooms lightly in oil, either using a silicone brush or oil spray. Then add them to the pan flat side down and fry for 6 minutes. Then flip and fry for a further 4 minutes or until cooked. Blot off the excess water with paper towel when cooked.
• Fry the halloumi slices for around 2 ½ minutes each side, until golden. You can do this in the same pan as the mushrooms, cooking in batches if you like, mushrooms first then transfer to a plate and cover with foil while you cook the halloumi (or they can be kept in the oven at 70ºc to keep warm).
• While those cook, make your pesto mayo in a small bowl stirring until well combined. You can double up if everyone will have it in their burger AND use it as a dip for chips or wedges.
• Lightly toast your brioche bun halves on the lowest toaster setting. When everything is ready, assemble your burgers, spreading the pesto mayo on either the top or bottom of the bun, add a couple lettuce leaves, a slice of halloumi and a mushroom.

AIR FRYER

• Preheat your air fryer on 200ºc. Spray the mushrooms lightly with oil and cook for 6 mins, then flip and cook for a further 5-6mins. Cook the halloumi for 5 minutes each side.

BARBECUE

• On a well oiled BBQ, cook the mushrooms for around 3 minutes on the flat side, then 3-4 minutes on the other side or until cooked. Grill the halloumi until golden both sides, about 3 minutes each side.

OVEN

• Preheat oven to 200ºc/180ºc fan/400ºf/gas 6. Coat mushrooms and halloumi lightly in oil and bake for 20 minutes, turning halfway.