Heat the ghee in a large non-stick frying pan over medium-low heat. Add the cumin and cinnamon and cook, stirring, for 1 minute or until aromatic. Add the curry leaves and cook for 30 seconds or until aromatic. Add the onion and season with salt. Cook, stirring, for 3-4 minutes or until soft.
Add the garlic, ginger, coriander and chilli. Cook, stirring, for 1 minute or until aromatic. Add the garam masala and turmeric. Cook, stirring, for 1 minute. Add the potato and cook, stirring, for 2 minutes or until well combined. Stir in the rice until coated. Stir in the stock. Reduce heat to low. Cook, covered, for 10 minutes or until the stock is absorbed.
Remove the pan from heat. Use a spoon to make 4 shallow indents in rice mixture. Crack 1 egg into each indent. Cook, covered, over low heat for 5-6 minutes or until white is just set but yolk is still runny. Serve with tomato, curry leaves and yoghurt, if using.