Delicious, hearty, and extremely healthy. The only drawback is that there's a fair amount of chopping -- I have very little time to make dinner during the week, so I usually do the chopping for this over the weekend, and then just start throwing things in the pot after work. This is a variation on a recipe from Mark Bittman's _How to Cook Everything Vegetarian_, but that recipe calls for regular potatoes and no onions. I really enjoy the flavor of sweet potatoes, and I think onions make everything better, so I do it this way. We often eat it over brown rice, but it's also good just by itself.
- Put the water/stock, lentils, and curry powder into a big pot over high heat. Cover. When it starts boiling, reduce the heat and bring down to a simmer. Keep it covered and simmering for approximately 10 minutes.
- Add the sweet potatoes, onions, and salt. Raise the heat until it returns to a boil, then reduce so that it's simmering again. Keep covered.
- Cook until the potatoes are soft, the lentils are tender, and most of the water/stock is absorbed, about 15 more minutes. If there's too much water, remove the cover so that some of the water can boil off. If there's not enough water, add more.
- Add freshly ground pepper to taste.