Wash the ajwain leaves, cut or tear them into small pieces.
Soak tamarind in water.
Cut tomato and keep it aside.
Take oil in a pan, add the mustard seeds. As it crackles, put cumin, asafoetida and turmeric powder. Grate the ginger in it and throw the curry leaves and green chill. Add tomato along with a little salt. Sprinkle a little water, it helps to cook them evenly. Give a stir.
Add the ajwain leaves.
Extract the tamarind pulp.
Put the tamarind juice, jaggery and pepper powder to it.
Let cook for sometime.
Add water to it.
Allow it to cook for sometime.
Serve it hot with steamed rice.