With their combination of onion, spices and rich chickpea flour (also known as besan flour or gram flour), the onion bhaji is a crunchy, satisfying savoury explosion. This simple recipe takes the traditional South Indian snack and reinvents it as a burger, slathered in a mint-spiked yoghurt raita, and sweet Spicy Mango Chutney, Tomato Kasundi, or whichever Indian condiment you prefer.
Leave out the raita to make the burger vegan.
Note: The Essential Ingredient Chickpea Flour is richly flavourful, and slightly coarser than other varieties. Add the water to the batter gradually and reduce the amount of moisture if needed.
To make the raita, mix the grated cucumber with the salt, then leave in a colander over a bowl to drain the liquid from it. After 30 minutes, squeeze out any excess liquid using the back of a spoon and discard the juice. Combine the salted cucumber with the yoghurt and mint, and set aside.
To make the bhaji, mix all the ingredients (onion, chickpea flour, coriander stems, baking powder, turmeric, cumin and salt), then add water gradually until the batter is well hydrated, but still holds together in a loose patty in your hand.
Heat 5cm of oil in a deep, heavy-bottomed saucepan until it reaches 180C (the dough will foam when it hits the hot oil, so using a saucepan is essential).
Use a soup spoon to scoop a small heap of onion batter, flatten slightly with the back of another spoon, and transfer carefully into the oil. Cook in batches, for 2 minutes per batch, or until golden brown all over and crispy at the edges. Lift carefully from the oil and transfer to paper towel. Sprinkle a little more salt over the finished bhaji.
Toast the inside of your bun tops and bottoms, then spread a little raita over the top of the bottom half of the bun. Add one or two bhaji to each bun, top with lettuce and coriander leaves, then spread Spicy Mango Chutney, Tomato Kasundi or your relish of choice inside the top of the bun, and close the burger. Serve immediately with cold beer or lassi.