Puree the thawed strawberries in a food processor or bender. *If you are using fresh strawberries please see notes below.
Whisk the water, lemon juice and arrowroot powder in a medium saucepan then add the strawberries puree. Bring mixture to a boil slowly over medium heat, stirring frequently.
Lower heat to medium low and simmer until it thickens, approximately 50 minutes. As it begins to thicken stir frequently to avoid burning. You will know it is done when you draw a rubber spatula through the center and it creates a hole that stays open for a few seconds and then fills back in. Once this happens remove from the heat and allow it to cool before storing. As it cools, it will continue to thicken. If your jam becomes too thick, add a little water. You can also return it to the stove and cook it longer if you want a thicker jam.
*If you are using fresh strawberries add them to the saucepan directly along with the water, lemon juice and arrowroot powder and heat for 5 minutes to soften them up. Puree mixture in your blender or food processor then return to the stove and follow step 3 and 4 above.Keep refrigerated in an airtight container for up to 2 months.