Take a non stick pan and dry roast the semolina on low flame for 5 min till u get a nice aroma.
Heat oil in a sauce pan and add 1 tsp mustard seeds (after it stops crackling) add cashew nuts, 1 tsp whole cumin, 1 tbsp finely chopped ginger, 6 curry leaves and 2 or 3 green chilies.
Now add onion and fry only till it is soft (not to be fried much) and then add chopped tomatoes. Fry till tomatoes melt and oil separates.
Add all the vegetables and fry for a minute followed by 1/4 tsp turmeric, 1 tsp red chili powder, salt, 1 tsp sugar, 2 tbsp lemon juice and stir well, add measured water and bring to boil. Check the seasoning (salt) by tasting the water.
Reduce flame, and slowly little by little add roasted semolina. Keep stirring while adding as to avoid any lumps.
Finally, add fresh coriander leaves, stir and place lid. Cook on low flame for 5 min and the switch off the gas. Let the upma stand for few more min before you open the lid.
Serve hot.