Chop the rhubarb into pieces about 1-2cm big and hull and half the strawberries
Place all fruit in a bowl along with the orange zest and the sugar. Cover with a clean tea towel and leave in the kitchen overnight.
Tip everything into a preserving pan and bring to the boil and bubble till you reach the setting point of 105C
Carefully ladle into sterilised jars
This recipe makes 500ml of jam and I estimate a serving as a 20ml tablespoon of jam so that's how the calories are worked out here.This jam will keep for up to a year, once opened store in the fridge and use within a month.I have used the French method of letting the fruit macerate with the sugar overnight, this makes cooking quicker and jam taste better.