Sautee the aromatics: Pour 2 tablespoons of oil into a large walled pan or pot and place it over medium-high heat. Once the pan/pot is hot toss in the garlic, ginger & cumin seeds. Sautee these ingredients for 1 minute making sure to not burn them.
Make the curry base: Add the onion and green chili to the pan/pot and continue to sautee everything until the onions start to turn translucent. Then add the tomatoes, chili powder, garam masala, turmeric powder, and salt. Keep sauteing these ingredients for a couple more minutes or until the tomatoes start to break down and form a thick sauce.
Toss in the vegetables and stir everything together so that they are coated in the curry base. Continue to sautee everything for a couple more minutes. Then add the water and stir so that dilutes with the curry base to form a sauce.
Let the vegetables cook: Let the sauce come to a boil then cover the pan/pot with a lid. Reduce the heat to low so that the sauce stays at a simmer and let the vegetables cook for roughly 30 minutes or until they are fork tender.
Once the vegetables are fully cooked take the pan/pot off of the heat. Taste the curry and add more salt if needed. Finally, sprinkle the chopped cilantro over top and stir to incorporate it with the curry.
Serve the mixed vegetable curry immediately and enjoy!