As with any recipe, the key is to get all of your ingredients prepped before you start cooking. This is one of those recipes that turns out best when you have everything ready! So peel and chop the sweet potatoes into dice-sized cubes, peel and chop the onion, open the can of tomatoes, rinse and chop the cilantro, get your spices out, a large soup pot,
Heat 3-4 tablespoons of oil in a large pot over medium heat. When hot, add onion, stir frequently. When onions begin to soften, add sweet potatoes. Saute, stirring frequently, cook for 3 minutes.
Add fresh ginger, fresh coriander, mustard, cumin, tumeric, dried coriander, and asafoetida. Cook for 1 minute, stirring constantly.
Pour in tomatoes and their juices, fill can with water and add to pot.
Add lentils, stir to combine all ingredients.
Increase temp to medium-high. Bring soup to boil, then lower to a soft rolling simmer. Cook gently, partially covered, for 15 minutes or until lentils are soft. If soup becomes too thick before lentils are done, add water 1/2 cup at a time until desired consistency is achieved.
Serve topped with chopped cilantro, 1 teaspoon each chutney and sour cream on top.
Cilantro and Tamarind Chutneys can be found at most grocery chains in the Indian department. Check out your local directory to see if there's an Indian grocery store in your area. I get my chutneys at The Himalayan Market on North Street in Burlington, VT.
w.o.w. -> expand your spice rack to include basic Indian spices. Here are my faves: black mustard seeds, asafoetida, cumin seed, fenugreek, coriander (whole and powder), turmeric, holy basil, and cardamom.