Cut the brinjal into medium size pieces.
Heat oil in a pan, splutter mustard seeds and add chopped garlic, green chilly and onion. Saute till the onion turns light brown in colour.
Now add brinjal and curry leaves. Saute till it becomes soft.
When the brinjals are soft add kashmiri chilli powder, turmeric powder, garam masala and salt as required.
Saute for 3-4 minutes in low flame.
Finally pour 3/4 cup water, cover and cook for 5 -10 minutes to get a thick consistancy.
Baingan Masala is ready now.