Prepare the pumpkin by cutting into quarters and scraping out the seeds.
Squeeze the juice out of the lemon quarters with a wooden spoon and then remove from the pan (remove any escaped seeds too).
Pot up into hot sterilised jars (makes just over 1 ltr which is 2 large jars plus a bit for tasting).
Place lids on immediately.
Ready to eat when cool although the flavours will mature on keeping.
Store in a cool dark place and once opened keep in fridge and eat within 2 – 3 months.
Sterilise jars by washing in hot soapy water (or take straight from dishwasher), fill with boiling water, empty and then place in oven for 20 minutes at 140°C where you leave them until the jam is ready. Washed lids should be sterilised with boiling water and then left to drain.