Rinse the rice, chana dal, toor dal, urad dal, and moong dal under cold running water until the water runs clear.

Place the rinsed grains and lentils in a large bowl, cover with water by 2 inches, and soak for 8 hours or overnight at room temperature for fermentation.

Drain the soaked mixture and transfer to a blender, add 1/4 to 1/2 cup water, and grind to a slightly coarse batter consistency.

Grate the bottle gourd and carrot, chop green chilies, mince garlic, grate ginger, and chop curry leaves while the batter is grinding.

In a large mixing bowl, combine the ground batter with grated vegetables, green chilies, ginger, garlic, salt, oil, asafoetida, sesame seeds, and curry leaves.

Cover the batter and let it rest for 1 to 2 hours at room temperature to continue fermentation and develop flavor.

Preheat the oven to 375°F and grease an 8x8 or 9x9 inch baking pan generously with oil or cooking spray.

Sprinkle baking soda over the rested batter, fold it in gently to incorporate, and pour the batter into the prepared pan, smoothing the top with a spatula.

Bake for 25 to 30 minutes at 375°F until the top is golden brown and a skewer inserted into the center comes out clean.

Remove from the oven and let the handvo cool in the pan for 5 to 10 minutes before cutting into pieces and serving.