Cut stems off strawberries and place strawberries in food processor. Process until it turns into a smooth puree. Place strainer over medium sauce pan and pour strawberry puree over it, with spatula press puree through strainer to speed up the process. Once puree is strained add sugar and mix. Place pot over medium-high heat. Watch closely, when puree begins to boil reduce heat to medium-low and allow to simmer for 20 minutes stirring occasionally. When time is up, pour puree in a heat proof bowl and allow to cool.