It can be made with a single dal or a combination of two or more dal. I have used tuvar dal or arhar dal(pigeon peas lentils) in this recipe. Below is the list of some dals which are used in making sambar. 1. Moong dal (Yellow moong lentils) or masoor dal (red/orange lentils) can be used to make sambar. 2. You can mix tuvar dal and masoor dal. Combining these two dals you will get a very different taste. 3. Combination of moong and masoor also tastes good. You can make different variations of sambar by using different dals and combinations of different vegetables. This is the beauty of this dish. Sambar will taste different due to its ingredients changes. You will not get bored with this dish.