Put oil in a pan and add cumin seeds and mustard seeds.
Now add onion and spring onion saute it.
Allow it to cool.
In a big bowl nix together potatoes,beetroot and carrot.
Add all the seasonings to it.
Add the onions to it.
Slightly wet the bread slices in water and squeeze excess water from it.
Add these slices to this mixture.
Roll out the patties in desired shape.
Roll them in semolina to cover them properly.
Fry the rolls and serve with dip of your chioce.
You can also add boiled peas to the mixture.