Wash  and cut the strawberries. Pour the strawberries into a medium sized pot and set it to boil. Take a potato masher, or grind them in a food processor, and start mashing all of the strawberries together. 

Add in the brown sugar and the juice from the lemon and stir all the ingredients together.  

Set it to boil, make sure you are seeing the bubbles boiling, while stirring every 5 minutes or so. Make sure it boils for about 20-25 minutes. 

Store them in a jar and refrigerate once its done boiling and the mixture starts to thicken.