Pressure Cooker Sambar (Indian Lentil Curry)

Combine 4 cups water, lentils, eggplant, turmeric, and salt in a pressure cooker. Close cooker securely and place pressure regulator over vent according to manufacturer's instructions. Heat until steam escapes in a steady flow and makes a whistling sound, about 10 minutes. Adjust temperature until regulator is gently rocking. Cook for 3 minutes and remove from heat. Let pressure release naturally according to manufacturer's instructions, 5 to 10 minutes. Unlock lid and remove.

Add remaining 2 1/2 cups water, tamarind paste, and chile powder to the pressure cooker. Close cooker securely and place pressure regulator over vent according to manufacturer's instructions. Heat until steam escapes in a steady flow and makes a whistling sound, about 10 minutes. Remove from heat. Let pressure release naturally according to manufacturer's instructions, 5 to 10 minutes. Unlock lid and remove.

Combine oil, dried chile, curry leaves, cumin seeds, mustard seeds, and asafoetida powder in a small saucepan over low heat. Cook until spices begin to sputter a bit, about 1 minute. Transfer spice mixture to the pressure cooker with the lentils. Season with salt.