Boil toor dal in water, with a pinch of turmeric. If you have a pressure cooker, nows the time to use it. Boil it till it can be mashed. Mash it partially and keep aside. Toast chana dal, coriander seeds in a dry pan. After the dal becomes golden brown, add the red pepper, fenugreek seeds, curry leaves and hing. Fry till they get toasted and aromatic. Coconut can also be toasted slightly to bring out the aroma. Dont let it brown. Grind along with coconut and tofu.
Cut veggies into 1x1 pieces. In case of okra, cut into 1 chunks. Regular onion can also be used halved and sliced. In a dutch oven, fry the onion/okra (other vegetables do not require this step) for a few minutes. Add some water and turmeric. Bring to boil.
If using tamarind pulp, soak in hot water for a few minutes and squeeze out the pulp and strain into the boiling water. If using paste, it can be directly dissolved in the boiling water.
Let it boil till it reduces by half. Then add the coconut ground with spices and let it boil again. Then, add the cooked toor dal and salt and vegan sugar. Bring it to boil and take off the heat.
In a small pan, heat a tsp of oil. Add mustard seeds and urad dal. After it splutters, turn off the heat add some torn curry leaves. Add this to the sambhar. Garnish with chopped cilantro. Yummy Sambhar ready!
May seem like some work, but its worth every bit of effort. All ingredients can be found in an Indian grocery store.