Answer
Salan me gravy banane k liye onions & tomato ka istamal kia jata hai, or baaz dafa dahi ko bhe use kia jata hai, agar aap ko zada gravy rakhni hai to salan me thodi zada pyaz istamal karein magar dehan rahay k zada pyaz k istamal se salan ka ziqa kharab bhe ho jata hai