Put the cumin seeds into a dry frying pan over a medium heat and stir until they are fragrant and have turned a shade darker. Tip into a mortar and grind to a powder with the pestle.
Blitz the mushrooms in a food processor. Put all the ingredients except the oil into a mixing bowl, knead well and combine thoroughly. Cover and refrigerate for 30 minutes or so. Divide into eight portions and form each into a burger shape.
To cook, you can shallow-fry the burgers over a medium heat in a frying pan or on a griddle. For a healthier option, lightly brush the burgers with oil and place on a rack under a hot grill. Turn halfway through cooking. In either case, the burgers should only take three minutes each side. Check they are thoroughly cooked: cut a burger through to the middle, it should be white with no trace of pink.
Recipe courtesy of Reza’s Indian Spice by Reza Mahammad, published by Quadrille (£17.99, hardback). Photos © Martin Poole.