oops; sorry for not replying; I used the one in HUgh Fearnley Whittingstalls book 2

Effectively 2kg tomatoes, 200g shallots, herbs to taste, and several garlic cloves sliced.  place halved etc on a baking tray  with oil and slow cook in oven until soft and cooked.  Sieve to get a passata; you should get about 1 litre. (very liquid often at this point)

Next, place passata in a preserving pan, add 100ml cider vinegar, 50ml lemon juice, 1tsp mustard powder (or 2tsps mustard) , 1 heaped tsp celery salt, 1 heaped tsp ground ginger, half tsp ground cloves and half tsp ground pepper.  Bring to simmering point then add 100g demerara sugar.  Once sugar has dissolved boil for 25 mins  until the thick but pourable consistency of ketchup.  Bottle in warm, sterilised jars.  Will keep 4 months.  If there is any chance of you keeping it longer (no chance here - it is too moreish!) then warm water bath the bottles as for any vegetable.

ENJOY!