Mix butter and sugar, till soft and fluffy. Add eggs to this, one at a time. Now add vanilla essence and mix well.
Sieve together flour, baking soda and salt. Add this to the above mixture and mix them well.
Add chocolate chips and stir thoroughly. Refrigerate the dough for an hour,
Grease the baking tray with a little oil. Put spoonfuls of the dough on the sheet.
Preheat the oven at 190 deg C for 2-3 min. Put the baking dish in the oven and bake for 8-10 min. Tatse to see if its cooked well, if not, cook for another 2-4 minutes.