Steps for preparation

Fill a large pot with lots of water. Add puffed rice and keep stirring for 30 seconds. They will turn softer and soak up water. If thicker variety is used, soaking should be done for 5 minutes to soften.
Squeeze off the water from with both your palms. After squeezing they should be just moist and no excess water.
Now heat oil in a pan. Then add mustard and cumin (optional). Also add chana dal, urad dal and peanuts. Fry peanuts and dals till golden and crunchy
Add curry leaves, green chillies, onions and fry till onions turn lightly pink.
Add tomatoes, turmeric and salt
Cover and cook till the tomatoes turn mushy. Then fry till the oil begins to leave the sides of the pan.
Lower the heat completely. Add puffed rice and mix well
Cover the pot and heat on a low flame until the puffed rice upma turns hot. Do not do it for longer it will get burnt
Turn off the heat. Add fried gram powder and coriander leaves. Mix well. Taste and add more salt if needed. Then squeeze the lemon juice.
Serve puffed rice upma hot or warm with mirchibajji, or even with plain yoghurt