Boil the halved baby potatoes in salted water until fork-tender, about 10-12 minutes. Drain and set aside.
Heat vegetable oil in a large skillet over medium heat. Add cumin seeds and mustard seeds, cooking until they start to pop.
Add the onion and sauté until softened and golden, about 5 minutes.
Stir in garlic, ginger, and green chilies, cooking for another minute until fragrant.
Sprinkle in turmeric, coriander, and garam masala. Stir well to coat the onions and release the spices' aroma.
Add the cooked potatoes to the skillet, tossing to coat them evenly with the spice mixture.
Season with salt, garnish with fresh cilantro, and serve hot.