Chickpea and Green Bean, Tomato Stew

I have no idea of the origins of this dish- neither literally, or ethnically..
It came to me from my dear friend M, she bought it along to a potluck picnic once.
I've been making it ever since. It's a nice, reliable 30 minute meal (who doesn't love 30 minute meals!?)..
The secret ingredient, which really transforms the whole dish- is white vinegar:
Don't ask me, in this case, I just follow the instructions.

Recipe
Ingredients:
1-2Tbs olive oil

1/2 onion, diced
1 clove of garlic, minced
2tsp cumin seeds
1/2tsp asafoetida
1 1/2 cups diced tomatoes (I used tinned organic)
2Tbs tomato paste
2Tbs water
1 can(400g) chickpeas, drained
2 handfuls green beans (or snake beans) split, and halved
4 small dried bay leaves
Salt and pepper to taste
1-2Tbs white vinegar

Basmati rice

Method:

1.Add oil and onion to frypan on medium heat. When softened, add garlic, cumin & asafoetida, and saute until onion is browned.

2.Add all remaining ingredients, except vinegar, and stir well to combine. Cover, and turn down heat just a little.

3.Boil water for rice, and cook per instructions.

4.By the time your rice is cooked, and drained, the green beans should be tender.

Add vinegar, and stir in well. Cook for 1 or 2 more minutes.

5.Serve, with rice.