Rinse the dal in a fine-mesh sieve, swishing it with your fingers until the water runs clear. Cook the dal with water in a pressure cooker on high for 10 minutes, then let it rest for 10 minutes before releasing the pressure. If cooking on the stovetop, simmer in a saucepan over medium-low heat for about 1 hour until the dal is falling apart. Whisk until mostly smooth.

Combine the moringa and tomato in a saucepan with enough water to cover. Boil until the vegetables are just starting to become tender, about 5 minutes.

Add the cooked dal, sambar podi, red chili, and salt to the vegetables. Simmer for 10 minutes, allowing the mixture to thicken and the flavors to integrate.

Heat the oil in a small pan over medium heat until it shimmers. Add the asafetida and mustard seeds, waiting until the seeds begin to pop and crackle. Reduce the heat to medium-low, add the garlic, and stir until it turns a light golden brown. Stir in the curry leaves and remove the pan from the heat immediately.

Pour the tempered spices and oil into the sambar and simmer for another 5 minutes, adding small amounts of water as needed to reach a pourable consistency. Stir in the tamarind concentrate and adjust the seasoning with salt and chili. Serve hot.