Add mustard seeds. When you hear the crackling sound of mustard seeds, it means they are getting fried.
Now add the cumin along with chana dal and urad dal. Fry till they start to brown a little.
Add cashews. By the time the cashews get browned the dals would also get browned.
Now add onions and fry till they become transparent.
Now add the green chilli, ginger, curry leaves. Fry for a minute.
Now add water to this mixture and let it come to a boil.
Add salt and sugar. If you want a sweeter taste, you can add more sugar.
When the water comes to a rolling boiling, lower the flame and add the roasted semolina to it, stirring continuously. The semolina should be added not at once but in 3-4 batches with a spoon to prevent lumps. Keep on stirring. The semolina will absorb water and swell and begin to cook.
If the mixture looks dry, then add some more water.
Reduce the flame and simmer the upma for 2-3 minutes.
Keep stirring so that the upma does not stick to the pan.