Courgette Curry (Zucchini Sabzi)

My daughter's Indian born SEN escort on her school bus shouted out 'Courgette Sabzi ' to me one day as she drove off after I told her I had a courgette glut.  With a couple of overgrown courgettes from the allotment last week, this seemed to ideal opportunity to try it out.  It is a mild curry, ideal for curryphobics?

4 medium courgettes, halfed lengthways and finely sliced
1 tbsp sunflower oil
1 large onion, quartered and finely sliced
1 large clove of garlic, crushed
1 tsp cumin seeds
1tsp brown mustard seeds (optional)
1 tsp turmeric
1 tsp ground coriander
1 tsp garam masala 
1/4tsp hot chilli flakes
1 tin chopped tomatoes
1tbsp tomato puree
Juice of 1 small lemon
1 tsp salt

In a large heavy bottomed saucepan, fry the cumin & mustard seeds in the sunflower oil until they start to pop.

Add the onion and garlic and continue frying for about 5 minutes then add the remaining dry spices for a couple more minutes until you can smell them.

Stir in the courgette and fry for 5 minutes, stirring frequently to make sure it doesn't catch.

Add the tomato puree, tinned tomatoes, 1 can of recently boiled water, lemon juice and salt.

Bring to the boil then simmer for about 10 minutes if you want the courgette still to be slightly crunchy, or longer if you want it softer.

As with all curries, it will be better if cooked the day before and reheated the next day.