This is incredibly delicious, and super healthy. This is adapted from Julie Sahni's "Classic Indian Cooking". It has less salt and oil than the original and less liquid - this dish is traditionally served like a stew, but I like it more saucy. If you prefer a soup, just add 1 more cup of water. To make this a more protein rich vegetarian meal, it's yummy with a can of chickpeas added along with the tomatoes. For the potatoes, use 1 large or 2 small potatoes.
You can serve with basmati rice, bread or just inhale it directly from the bowl. This makes 4 main dish portions, or 6-8 as a side dish.