I think in India Sambar is traditionally made with toor dal (hulled, split pigeon peas). If you can't find toor dal in your area, it's available in online stores like ishopindian.com You can also use red lentils or split mung beans or chana dal. There are many recipe variations for Sambar, thick or thin or somewhere in between. Some are just dal (split pea/lentil) puree with spices. Others have added vegetables. This recipe uses curry leaves. If you can't find curry leaves, you can substitute bay leaves or just omit. The flavor will be different, but still good.
1 cup yellow split peas, rinsed
1 Tbsp oil, divided
1/2 tsp turmeric
1 Tbsp sambar masala*
1 tsp black mustard seeds
1 tsp cumin seeds
1 tsp salt
4 red arbol chiles (small dried red chiles)
1 sprig curry leaves
1 small onion, chopped
4 cloves garlic, minced
1/2 Tbsp minced ginger root
1 Roma tomato, diced small
1/2 small cauliflower, chopped bite-size pieces (about 1 1/2 cups)
1 medium sweet potato, peeled and cut in 1/4-inch dice (about 1 1/4 cups)
2 small Indian eggplants, peeled, diced (about 1 cup)
1 Tbsp tamarind concentrate
1 cup warm water
2 Tbsp chopped cilantro
Precook sweet potato in microwave 5 minutes. Set aside.
Cook yellow split peas with 3 cups water, 1/2 Tbsp oil and 1/2 tsp turmeric in pressure cooker 8 minutes; quick release pressure and set aside. (If your pressure cooker doesn't have a jiggle top, you can probably omit the oil. My pressure cooker has a jiggle top, so it's included to prevent foaming and clogging the vents. You can also cook without oil in a regular pan on stovetop until very tender. Peas should be mostly puree.)
In nonstick skillet, heat remaining 1/2 Tbsp oil. Add black mustard seeds and cumin seeds. When they pop, add chiles and curry leaves. Stir until leaves begin to crisp. Don't burn. Add onion; cook and stir a minute or two, then add garlic and ginger. Cook 1 minute, then add tomato. Cook 2 or 3 minutes until tomato begins to break down. Add cauliflower and eggplant. Cook and stir 2 to 3 minutes, then stir contents of skillet into cooked peas along with tamarind concentrate dissolved in warm water, reserved sweet potatoes, sambar masala powder, and salt. Simmer over medium-low, stirring often and adding water if necessary to prevent scorching, for 25 to 30 minutes til vegetables are very soft. For thinner sambar, add additional water. Add cilantro and serve. You can serve this with basmati rice or Indian bread and chutney.
Serves 4. Per 1/4 recipe 447g serving: 281 calories, 4.5 g fat, 17 g fiber, 15 g protein, 56 mg sodium
*You can buy sambar masala spice blend prepackaged. I used MDH brand. There are also numerous sambar masala recipes online.
Note: You can vary vegetables to taste or by what's available. Carrots, green beans, squash, green peas, potatoes, and okra, as well as various Indian vegetables, are often used. Many sambar recipes also include coconut.