- To begin, soak the chana dal for half an hour. Boil it with salt, turmeric powder, and 1 tsp oil until almost cooked. It should still have a bite not be mushy. Drain and keep aside. Save the liquid. 
- Peel and dice the lauki (bottle gourd) into cubes. Soak them in water so that they don't colorize. 
- Heat 2 tbsp of oil in a pan. Add in a bay leaf. Add the achari masala - mustard seeds, cumin seeds, fennel seeds, fenugreek seeds, and nigella seeds. Allow them to crackle. 
- Add in finely chopped onions and chopped green chillies. Saute until the onions are translucent. 
- Add in ginger garlic paste. Saute until the onions colorize. Do not brown. 
- Next, add finely chopped tomatoes. Mix well. Add the salt. This helps tomatoes cook faster. Cook until the tomatoes soften. 
- Now add in the dry masalas - Kashmiri red chilli powder, cumin powder, coriander powder, and turmeric powder. Mix well. 
- Add a bit of water. Cover with a lid and cook until the oil starts appearing on the sides. 
- Next, add the diced lauki. Mix well and saute for a few minutes. Add 1/2 cup water. Cover and cook until the lauki is tender. 
- Now add in the boiled chana dal and tamarind pulp. Saute. Add some leftover water from the dal you boiled. Cover and cook until done. 
- Finally, add garam masala powder. Mix well. Adjust the gravy as per your taste. 
- For the tempering, heat oil in a tadka pan. Add in cumin seeds, whole red chillies, and curry leaves. As they begin to crackle, pour this tadka over the dal. 
- The Achari Lauki Chana Dal is ready to serve. Garnish with chopped coriander leaves. Serve hot with puris or parathas.