Slice strawberries and place in a saucepan and add just enough water to cover. Heat this mixture over a medium heat but don't boil or the texture of the strawberries will get mushy. Add the sweetener, and lemon juice and (optional) jam. Heat this mixture slowly until liquid it is VERY HOT. This allows the flavor and color to develop well and the thickener will incorporate better.
Remove from the heat, and separate some of the fruit juice into a separate bowl, sprinkle the 3/4 teaspoon xanthan gum carefully over the top, and whisk together until it is thickened. If it is not as thick as you would like it to go ahead and add more xanthan gum up to 1 teaspoon.
Remember it will thicken more as it cools. Return the juice, now syrup, to the berries and stir then place in a jar with a tight-fitting lid.
*The amount of xanthan gum needed will vary according to your preferences. 1/2 teaspoon will give you a thin-ish syrup once it has chilled. 3/4 teaspoon is my preference but if you want an almost jelled texture 1 teaspoon can be used. The more xanthan gum you use the less of the berry color will shine through.
* This syrup keeps splendidly in the refrigerator to top your favorite goodies!
Recipe by Nana's Little Kitchen at https://www.nanaslittlekitchen.com/easy-breezy-strawberry-syrup/