In a large (lidded) nonstick skillet over high heat, warm the oil. Once the oil is hot, add the potato and half the salt and let cook, undisturbed, until the cubes develop a golden-brown crust on the bottoms, 3 to 5 minutes.

Lower the heat to medium, give the potatoes a toss and add the green beans, the remaining salt and 1/4 cup of water. Cover and let cook for about 3 more minutes, until the beans are starting to soften but still a little crunchy, and the potatoes have a little firmness but can be pierced with a fork.

Add the coriander, cumin, pepper, garlic and ginger. Toss to coat the potatoes and green beans, then let cook until you can smell the strong fragrance of the spices, ginger and garlic, about another minute.

Turn the heat down to low, stir in the almond butter, and as it melts, toss it with the vegetables to coat. Cook the sabzi for another minute or two, just to let the almond butter dry out a little and form a crust on the vegetables.

Remove the pan from heat, and sprinkle the top with lime juice and a light dusting of chaat masala, if using. Serve by itself, or with rice or roti alongside.