I put this together when all I had in my kitchen cupboard were some cans of beans.
Cooks in 40 minutes
2 red onions
3 cloves of garlic
2 green/red chillies
200g chopped tomatoes (1/2 can)
220 green beans
400g red kidney beans (1 can)
400g black eye beans (1 can)
400g butter beans (1 can)
Heat the oil in a saucepan. Add the cumin seeds and fry for 30 seconds. Roughly chop and add the chillies and garlic, and fry for 1 minute. Dice and add the onions and cook until softened. I find that if you add a pinch of salt at this point, it really brings out the moisture in the onions.
Add the remaining spices (turmeric, cinnamon, and curry powder) and cook for another minute or two. Chop and stir in the green beans. Add the chopped tomatoes and cook for 5 minutes.
Drain and wash the black eye beans, red kidney beans and butter beans. Stir them into the saucepan. You can use whatever sort of beans you like/have.
Add in the coconut milk, water and salt, and let the curry simmer for 30 minutes till it has thickened and the green beans have cooked. You can serve it with some rice, naan or just eat a big bowlful by itself!