Chop vendakkai (okra or ladies finger) into big pieces. Fry the vendakkai (okra or ladies finger) in oil until they don't change color and keep it aside.
Soak tamarind in 1/2 cup of water for 20 minutes and get the tamarind juice.
Pressure cook (or cook) masoor dal, water as needed and turmeric powder until its cooked well. Remove from cooked dal from heat (stove). Add the tamarind juice, sambar powder to cooked dal. Mix well and keep it aside.
Heat oil in a pan. Add mustard seeds, cumin seeds, asafoetida powder. Once the mustard seeds stop splattering add the shallot (sambar onion) and sauté until onion becomes translucent (golden brown).
Now add the garlic, green chili, curry leaves, 1/2 coriander leaves and sauté until the garlic raw smell is gone.
Now add tomato and sauté until the tomato becomes mushy.
Now add the cooked dal and bring to boil. Cook the dal until raw smell of the tamarind is gone and the right thickness to your preference is reached.
Now add the fried vendakkai (okra or ladies finger). Let sambar boil for couple of minutes.
Now add rest of the coriander leaves. Remove vendakkai sambar from heat (stove) and serve.
Instead of frying Vendakkai you can just sauté it in a pan as well.