Heat oil in a skillet, add onion and cook till they turn translucent, about 2~3 minutes. Stir in ginger+garlic paste and cook for another minute.
Add the tomato puree or chopped tomatoes, turmeric, chili powder, ground coriander, crushed kasoori methi and salt. Cover and cook on medium-low flame until oil starts to separate around the edges.
If using canned beans, rinse and drain well. Add to the tomato mixture along with cup of water. Simmer for 5~7 minutes or low flame until the mixture is thick. Add garam masala just before turning off the heat.