I often find myself craving spicy Indian food during colder months. Growing up, my mom made this dish with regular potatoes, but I love the bright color and creamy texture that sweet potatoes bring. Even if you're not familiar with Indian cooking, this is still a simple dish to make and doesn't require too long of a list of spices! For the tomato paste, you'll only need a little, so I recommend purchasing a brand (I like Amore) which comes in a toothpaste-like tube instead of a can. Serve this "sabji" (which simply means "vegetable dish") with store-bought naan or pita bread. —bluejeangourmet
Prep the vegetables: peel & dice the sweet potatoes into roughly 1-inch chunks, then wash & remove the ends from the green beans, chopping them into inch-long pieces.
In a large, heavy-bottomed pan (with a matching lid), heat the oil over medium-high heat. After 3-4 minutes, the oil should be quite hot but not smoking. Throw in the mustard seeds & sprinkle in the asfoetida. It's essential to heat these two ingredients at the outset and let them get very hot or they will make the whole dish taste bitter.
Turn down the heat to medium; add ginger. Cook until the ginger begins to soften, then add the sweet potatoes, sambar powder, & water. Toss to ensure that the potatoes are well-coated with the spices.
Cover the dish, turn the heat down to medium-low, and allow the sweet potatoes to cook until just tender, about 15 minutes.
Add the green beans and cook for another 5-8 minutes, including more water if necessary. Once the green beans are bright and cooked through, fold in tomato paste to bind the dish. Taste the dish for salt & season accordingly.