Put the chickpea flour, rice flour, salt, coriander, chilli powder, turmeric, cumin and fresh chilli in a large mixing bowl and whisk together.
Measure 175ml (3/4 US cup) of water a little at a time, whisking until you have a thick, pancake-like batter - you might not need all of the water. Leave to rest for 10 minutes.
Prepare the oil in your deep fat fryer or a large, high-sided saucepan. It’s no more than one third full to allow for safe expansion during heating and cooking.
Heat the oil to 180C (355F) or until a little bit of batter dropped into the oil bubbles.
Put a few mushrooms into the batter and turn so that they are well coated. Don’t dip all of them at once as you’ll overcrowd the pan. Aim for 4-6 pieces at a time.
Lower the coated mushrooms into the oil slowly so that they don’t drop straight to the bottom and stick.
Fry for 8 minutes until crisp and golden, turning gently as needed.
Lift from the pan using a slotted spoon or straining spoon and place on a plate lined with kitchen paper to allow the oil to drain.
If you like, you can place the drained pakora on a baking sheet in a low oven to stay hot and crisp while you fry the rest of the batch.