Wash the strawberries well under running water. Remove the green tops and chop into small pieces. Leave some strawberries as whole to get the chunky bits.
Add the strawberries, sugar, and lemon juice into a wide pan. Mix gently and let sit for 5 minutes to release juices.
Place the pan on medium heat. Stir slowly as the mixture begins to heat and the sugar dissolves.
Once the strawberries soften, mash them using a spoon or masher to your desired texture.
Reduce heat to medium-low and let the mixture simmer. Stir often to prevent sticking or burning.
Continue cooking for 15 to 20 minutes until the mixture thickens and turns glossy.
Test the jam by placing a small amount on a cold plate. If it holds shape and does not run quickly, it is ready.
Turn off heat and allow the jam to cool completely. It will thicken more as it cools.
Transfer to a clean, dry glass jar and store in the refrigerator.
