To make the curry: Select the high Sauté setting and heat the oil. Add the onion and salt and sauté until the onion turns translucent, about 5 minutes. Cover the pot with a glass lid (or other nonlocking lid that fits) to speed up the process. Add the ginger and garlic and sauté until aromatic, about 1 minute. Add the tomato puree, chile powder, turmeric, and garam masala. Press the Cancel button to turn off the Instant Pot. Pour in the water and stir well with a wooden spoon, nudging loose any browned bits from the pot bottom.