Wash the fresh strawberries. Remove the green top (crown). Wipe clean and pat dry with a kitchen towel. Make sure they are not wet or moist.
Next, finely chop the strawberries. Cut and discard the inner white part of the strawberries. This step of removing the white part is called 'Hulling Strawberries.' If there is no white part inside the strawberries, no need to hull them.
Transfer chopped strawberries to a wide mixing bowl. Add granulated white sugar. Mix nicely. Cover and set aside for 20 - 30 minutes.
After 20 - 30 minutes, sugar will be completely dissolved with the fruit and a pink color juice will be released. Do not rush this process.
Add lemon juice and mix nicely. Transfer the strawberries along with all the pink liquid to a saucepan. Turn on the stovetop heat to low.
Start cooking the jam. Stage 1, the jam will be watery, with big chunks of strawberry, and white foam on top. Keep cooking on low heat, while stirring at regular intervals.
Slowly, the white foam will start reducing, the texture of the jam would thicken a bit. Use a potato masher or a ladle to gently mash the strawberries. Keep stirring at regular intervals.
After 15 - 20 minutes on low heat, the white foam on top will disappear, strawberries mashed nicely, and the jam will start sticking to the spoon. Turn off the heat.
To check the consistency of the jam, spread a big tablespoon of strawberry jam on a metal plate. The strawberry jam should be thick, doesn't drop off easily, and will stick to the plate. Else continue to cook further.
Allow the strawberry jam to cool down completely at room temperature. Store the cooled strawberry jam in a clean, sterlisied glass jar with a tight fitting lid.
Serve strawberry jam immediately or store in the refrigerator.