In a large bowl, rinse moong dal and rice until water runs mostly clear, about three times. Add in fenugreek and cover mixture with cold water by 2”. Let sit for 30 minutes to 1 hour.
In a medium pot over medium heat, heat oil. Add garlic and fry until lightly golden, stirring frequently to prevent burning, 2 to 3 minutes. Transfer garlic pieces to a plate and retain oil in pot.
Add all seeds, coriander, pepper, cinnamon, white pepper, turmeric, asafoetida, ginger, and kala namak, stirring until toasty, about 1 minute. Add in tomato and cook until they begin to fall apart, 4 minutes.
Add drained rice, moong dal, fenugreek, and 4 cups water and bring to a boil. Reduce heat to low, cover with a lid, and let simmer, stirring occasionally, until rice and dal are soft and falling apart, 25 minutes. Optionally, stir in remaining ½ cup water to loosen khichdi to desired consistency.
Serve with garlic chips, and cilantro if desired.