Rinse and soak the Short-Grain Rice, Chana Dal and Urad Dal together in enough Water to cover for 4–6 hours (or overnight).
Drain the soaked grains and lentils and grind them with Plain Yogurt, peeled Ginger, chopped Green Chili, Turmeric Powder and a pinch of Salt to a smooth, thick batter; add a little Water as needed to reach a pourable but dense consistency.
Transfer the batter to a bowl, cover and leave in a warm place to ferment for 8–10 hours or until slightly risen and airy.
Grease a steaming tray or cake pan with Oil and pour in the fermented batter, smoothing the top. Steam over boiling water for 15–20 minutes (or until a toothpick comes out clean).
While the dhokla steams, prepare the tempering: heat a couple of tablespoons of Oil in a small pan, add Mustard Seeds and let them pop, then stir in White Sesame Seeds, a slit Green Chili, Curry Leaves and a pinch of Asafoetida.
Add about 1/2 cup Water, Sugar, a squeeze of Lemon Juice and more Salt to taste; simmer briefly until the sugar dissolves and you have a light, tangy syrup.
When the dhokla is done, remove it from the steamer, pour the hot syrup and tempering evenly over the top so it soaks in, and let it rest 5 minutes.
Cut into squares or diamonds and garnish generously with chopped Coriander and grated Coconut before serving warm or at room temperature.
