Drain the chickpeas and dry on a kitchen towel. Grind the chickpeas along with garlic, coriander leaves, parsley, spring onion greens and breadcrumbs in a food processor to a coarse mixture.
Add soda bicarbonate and cumin powder and mix well. Season with salt, pepper powder and paprika.
Knead the mixture well and allow it to refrigerate for a couple of hours. Take the mixture in a tablespoon dampened with water and shape it from top with another damp tablespoon.
Many falafels can be shaped like this and stored on a greased plate in a refrigerator prior to frying. Heat sufficient oil in a kadai and deep-fry the falafels till golden brown.
Drain and place on an absorbent paper and set aside. Mix all the ingredients of yogurt sauce and chill till required.
Apply salt to cucumber ribbons and set aside. Cut the burger buns into half and apply butter. On the base half of each bun place a lettuce leaf, quartered cheese slice, cucumber slice and tomato slice.
Place fried falafel patties on it and top with yogurt sauce and cucumber ribbons. Cover each with upper half of the buns. Serve immediately.