First warm the milk in microwave for 10 minutes. Then pour the hot milk into a saucepan and bring it to a boil. This is a tip from my cook as it will prevent milk from getting burnt at the bottom of the vessel.
Simmer the flame/heat and add vinegar, 1 tablespoon at a time. Mix gently. Don’t over swirl or stir it. Keep adding vinegar until whey separates. You can add more vinegar as per needs. Whey will be like light blue liquid.
At this point, switch off the flame
Arrange the colander over a sink. Pour the paneer through a muslin cloth or kitchen towel to separate them from whey.
Take another container where the colander can fit inside. Now, invert the colander, place the muslin cloth with paneer on top of it and place something heavy (like grinder stone, mortar & pestle) on top to release all the excess whey/ water, takes about 1-2 hours.
Use immediately or store in water in fridge for 2-3 days. Storing in water keeps them from drying. Again a useful tip from my cook.