Soak ½ cup of Toor (arhar) dal in a bowlful of water for 15 minutes or so. When the dal swells up a bit, wash it nicely with water and keep aside.
Now, heat 2 tbsp of cooking oil in a pressure cooker on a medium flame. When the oil heats up, add ½ tsp of cumin seeds, 2 pieces of bay leaves, 3 pieces of green chilies (whole), and ¼ tsp of asafetida (hing) to it. Mix them and fry for about 20 seconds or so. Now, add 1 tsp of garlic (finely chopped), 1 tsp of ginger (finely chopped) and 12 pieces of curry leaves to it and fry for another 20 seconds or so.
Then add ½ cup of onion (2 medium size onions, very finely chopped) to it. Cook it until the onions turn slightly golden brown. When it does, add ½ cup of finely chopped tomatoes. Mix and cook them for about 3 to 4 minutes until the tomatoes turn soft. (Pro tip: Finely chopped tomatoes cook fast).
Now, turn the flame to low and add ½ tsp of turmeric powder, ½ tsp of red chili powder, ½ tsp of coriander powder, and ½ tsp of garam masala powder to it and mix them nicely with the other ingredients. Cook them for about a minute or so.
At this stage, add the soaked and washed Toor dal. Mix and cook the dal on a low flame for about 2 to 3 minutes. (Pro tip: Keep the flame low at this stage or else the grains of the dal will stick to one another).
Now, add 2.5 cups of water and 2 tsp of salt to it and give it a nice mix. Cover the pressure cooker and cook it on a medium flame up to 6 whistles. Turn off the gas stove then and let it cool down completely. (Pro tip: Do not use more than 2.5 cups of water for ½ cup Toor dal).
Check the texture of the dal. It should be smooth. (Pro tip: If the consistency is not smooth, cook it for a couple of minutes more without the lid this time and mash it with a whisker as well. If it is too thick for you, you can add warm water to it and dilute it a bit).
Now, to make the tadka, take a tadka pan and heat 2 tbsp of ghee (clarified butter) in it. When the ghee is hot, add 1 tablespoonful thin slices of garlic and ginger. Fry them until golden brown color. Pour it to the dal immediately and mix it nicely.
Now, add ¼ cup of finely chopped fresh coriander leaves to it. Cover the lid of the pressure cooker.
Now, heat a piece of charcoal on the flame for about 1.5 to 2 minutes. Put it in a small and light stainless-steel bowl and place it on the dal gently. Then put 1 tbsp of ghee on the burning charcoal and close the lid of the pressure cooker immediately and leave in that way for 2 minutes.
Remove the bowl of charcoal from the dal very carefully, give it a final mix and transfer it to a serving bowl.
Finally, before serving, make the tadka again as you did before, but this time, add 2 pieces of dry red chilies. Also, before pouring the tadka to the dal, tilt the tadka pan a bit to separate the hot ghee, add ½ tsp of red chili powder, stir it for a few seconds, mix it with the other ingredients and then pour it to the dal.
Your tasty and spicy homemade dal tadka is ready now. Serve it hot and enjoy it with hot jeera rice.