Microwaved Blackberry Jam

Place 450g washed blackberries and 1tbsp lemon juice in a large microwavable bowl and microwave for 6 minutes until soft. Stir in 350g sugar. Microwave uncovered for 7 minutes. Remove and stir well. Microwave again for a further 7 minutes. Remove, stir then microwave for 2 minutes. Cool sightly until able to transfer into clean jars. Makes l lb.