Wash bhindi in water and dry it using cloth or paper napkin. If possible, complete this process 2-3 hours prior to cooking. Remove head and tail and chop it into 1/3-inch thick round circles.Heat oil in a non-stick pan or heavy based kadai over medium flame. Add cumin seeds and when they begin to crackle, add chopped garlic. Sauté for 30 seconds.Add chopped bhindi and mix well.
Cook on medium-low flame until bhindi turns dark green and shrinks. It will take approximately 6-8 minutes. Stir in between occasionally.Add chopped tomatoes, turmeric powder and salt; cook until tomatoes turn tender, approximately 2 minutes.
Add red chilli powder, garam masala powder and coriander powder; mix well. Cook for a minute over low flame and turn off the flame.
Transfer prepared bhindi bhaji to a serving bowl. Garnish with coriander leaves and serve with roti or paratha.