Put the onion, ginger and garlic into a food processor.
Add the coriander and lemon grass.
Add the cumin, turmeric, fenugreek, cayenne pepper, cinnamon and brown sugar.
Add the lime juice and soy sauce.
Blitz until you have a yellow paste.
Make the vegetarian yellow curry
Put the potatoes a medium pan.
Cover with cold water.
Boil for 5 minutes to start them cooking, drain and set aside until the sauce is ready.
In a large frying pan (one with a lid) heat the oil, then add the sliced onions.
Fry gently for 5 minutes until beginning to soften.
Add half to all of the curry paste to the onion and continue to fry for 5 more minutes until the onion is nicely soft and the paste is aromatic.
Add the coconut milk.
Stir well, taste and season with a pinch of salt and pepper.
Add the potatoes, broccoli and green beans to the sauce.
Mix well, cover and simmer for 10 minutes until the potatoes are cooked.
Add a splash of water if your sauce seems too dry.
Serve with your favourite rice
If you prefer a saucier curry, you can double the quantities of paste, onions and coconut used.If you fancy varying this recipe each time you make it, you can include other vegetable combinations: how about cauliflower potato & baby sweetcorn? Or carrot, potato and green peppers?