Prepare the Strawberries: Wash the strawberries thoroughly, remove the stems, and cut them into quarters.
Cook the Jam: In a medium saucepan over medium heat, add the strawberries, sugar, vanilla extract, and lemon juice. Stir occasionally, allowing the strawberries to release their juices.
Simmer Until Soft: Let the mixture cook for about 15-20 minutes, or until the strawberries become soft and begin breaking down.
Blend or Mash: If you prefer a chunky jam, use a fork or potato masher to lightly break down the strawberries. For a smoother jam, blend the mixture in a blender until it reaches your desired consistency.
Thicken the Jam: Return the blended or mashed mixture to the pan and simmer for another 10-15 minutes, stirring frequently until the jam thickens slightly.
Cool and Store: Remove from heat and allow the jam to cool completely before transferring it to an airtight jar. Store in the refrigerator for up to two weeks.