Heat ghee in a small pan. Sprinkle asafoetida and stir quickly, adding the rest of the ingredients – cumin, cinnamon, green chillies and onions. Fry on a high flame for 4-5 minutes, until onion is slightly brown. Stir in the red chilli powder and garam masala if using. Transfer this tempering over the cooked dal + ridge gourd. Season with salt, around 1/2 teaspoon and simmer for 1-2 minutes, thinning with 2-3 tablespoons of water if required.