Boil chana dal with 4 cups of water till done (soft but not mushy). Reserve.
In heavy bottom pan, heat oil, add mustard seeds, cumin seeds, nigella seeds, fennel seeds, fenugreek seeds and whole red chilies, allow them to crackle
Add add onion and fry till translucent
Add ginger garlic paste and fry for few minutes until raw smell goes off.
Add tomatoes and fry on high heat for 3-4 minutes until soft.
Add turai ( ridge gourd) and fry for 2 minutes on high heat
Add turmeric, amchoor , achaari masala and red chili powder, mix
Add boiled dal and mix well.
Adjust the consistency of the dal and season with salt.
Bring it to boil, cover and simmer for 20-25 minutes.