1. In a mixing bowl, whisk together the besan, soy milk, water, lemon juice, ginger, green chilli, turmeric powder, salt, and asafoetida until completely smooth.
2. Pour the mixture through a fine strainer into a heatproof bowl or steel container.
3. Set up your steamer or a large pot with water and a steaming rack. Bring the water to a boil.
4. Place the bowl of batter onto the rack. Cover the bowl with a plate and close the steamer lid.
5. Steam on medium-high heat for exactly 15 minutes.
6. Carefully remove the hot bowl from the steamer. The mixture will look thick and set.
7. Immediately take a sturdy whisk or spoon and vigorously beat the hot mixture for about 30 seconds until it becomes smooth, glossy, and spreadable.
8. Test the mixture first, if not ready, steam for another few minutes.
9. While it is piping hot, drop a large ladleful of the batter onto your prepared surface (steel plates or kitchen counter). Using a palette knife, a flat spatula, or the back of a flat bowl, spread the batter as thinly and evenly as possible.
10. Let the spread batter cool and set for about 4 to 5 minutes.
11. Once cooled, use a sharp knife to cut it into long, parallel strips (about 1½” to 2″ wide).
12. Gently lift the edge of a strip and roll it up tightly into a cylinder.
13. Place the rolls on your serving platter.
14. Sprinkle the roasted mustard seeds, roasted sesame seeds, and finely chopped coriander leaves evenly over the arranged khandvi rolls.
15. Serve with coriander mint chutney.

Serves 3-4