Bring a 20cm or 8" saucepan of well salted (1-2 teaspoons in a pan this size) water to the boil.
If your potatoes are larger than bite-size, cut them in half or quarters.
Throw in the potatoes and parboil for 10-12 minutes.
Cut the carrots into bite-sized pieces and throw them in with the potatoes for the final 2-3 minutes.
Drain the carrots and potatoes and set them aside.
Top and tail the onion and cut it into 8 wedges.
Mash the garlic into a paste.
Heat a wok over a high heat, and when it is hot, add the oil. Throw in the curry leaves, dried chilli peppers and cinnamon stick and cook for 30 seconds.
Add the garlic and fry for another 30 seconds.
Add the potato, carrot, and onion to the pan and then cook for 5 minutes, stirring every minute or two.
Throw in the onion seeds, gram flour, chilli powder, cumin, coriander, turmeric, black pepper and salt and cook stirring continuously for 1 minute.
Pour in the tinned tomatoes and water, add the brown sugar and season with salt to taste.
Sprinkle in the dried fenugreek, stir, reduce the heat to medium and allow to simmer for 15 minutes.
Cut the green beans into 3-4cm (1½") lengths.
Cut the courgette into bite-sized pieces.
Add the green beans and courgette to the curry and cook for 3-4 final minutes before serving.