In a large, flat-bottomed bowl whisk together the plain flour, corn flour, baking powder, salt, herbs and spices.
Add in the water and mustard and whisk until there are no lumps remaining.
Trim the brown roots from the mushrooms and slice lengthways through the base into 6 thin slabs.
Working one by one dip the mushroom slabs into the batter and toss to coat completely.
Fill a medium-large frying pan with around 1cm of vegetable oil. Turn the heat to medium and heat the oil until around 350F.
Carefully add half of your battered mushrooms to the pan and fry for around 2-3 minutes on each side, or until golden all over.
Carefully remove and dry on a plate lined with kitchen towel. Repeat with the remaining mushrooms.
Add a handful of shredded lettuce on top of each mini wrap. Top with a generous drizzle of sriracha mayo, or your sauce of choice, and a bundle of crispy mushrooms. Enjoy!