Boil salted water in a large pot, add waxy potatoes, and cook for 10-15 minutes until tender but firm. Drain and cool slightly.

Blend fresh tomatoes, garlic, ginger, and a pinch of salt and pepper in a food processor until smooth.

Heat oil in a large frying pan over medium heat. Sauté onions, red chilis, mustard seeds, garam masala, and cumin for about 5 minutes until fragrant.

Add cooked potatoes and blended tomato mixture to the pan. Stir to coat and cook on medium heat for 10 minutes until browned and crispy.

Transfer to a serving plate and garnish with fresh cilantro. Serve warm.