Heat the oil in a large saucepan, then fry the onion and celery gently for 10 minutes until softened, stirring frequently. Tip in the cumin (reduce cumin if having hot flushes) and fry for another min.
Turn up the heat, and then add the stock, tomatoes and chickpeas, plus a good grind of black pepper. Simmer for 8 minutes.
Throw in broad beans and lemon juice, cook for a further 2 minutes.
Season to taste, then top with a sprinkling of lemon zest and chopped herbs. Serve with flatbread.