Take a wide pan and add cooking oil in it.
Add bell pepper and onion, both cut into Juliennes i.e. length wise.
NOTE : It is not necessary to have all three colours of bell pepper. You can only add the green one as it is very common and easily available.
Saute the bell pepper and onion for two three minutes on high heat.
Thereafter add tomato cut into Juliennes.
Saute for 2 minutes.
Remove the sauted veggies from the pan and keep it outside.
Add butter in the same pan.
Add cumin and let it splutter.
Then add tomato paste, red chilli powder, turmeric powder, salt and coriander powder.
Mix well.
Cook till tomato paste start leaving the sides of the pan and begins to release oil.
Add curd.
Keep whisking otherwise curd will curdle.
When curd begins to boil, stop whisking as it will not curdle now.
Once oil is seen separating from curd as well, add cashew paste. Cook for a minute.
Then add khoya, cream and sugar. Mix well.
Now add sauted veggies and paneer.
Give it a gentle mix without breaking paneer.
Lastly add garam masala and coriander leaves.
Mix and just simmer for a minute only.
Reshami paneer is ready. Enjoy.