Sauce or ketchup?
For sauce chop up some onions and cook in butter/olive oil slowly for 10 mins or until translucent. Meanwhile skin (some de-pip as well) and chop up the toms, then add to the onions with some salt and pepper on a low heat for 20 mins or so.
Depending on availability and flavour preferences add any or all of the following:
- Finely chopped/crushed garlic
- Basil, Thyme, Bayleaf
- Red Wine
If ketchup then James Martin has a good recipe -
250ml/8fl oz cider vinegar
1 bay leaf
½ tsp ground coriander
½ tsp ground cinnamon
8 tbsp Demerara sugar
1.5kg/3lb ripe tomatoes, quartered, seeds removed
1 tsp salt
1 tbsp English mustard powder
1 garlic clove, crushed
Tabasco sauce
2 tbsp tomato purée
½ tsp cornflour, if necessary
For the tomato ketchup, place the vinegar, bay leaf, coriander, cinnamon and sugar into a heavy-based saucepan and bring to a gentle simmer.
Add all of the remaining tomato sauce ingredients, except the cornflower, and bring to the boil, stirring occasionally to prevent any sticking or burning.
Once boiling, reduce the temperature and simmer, stirring frequently, for 30 minutes. (NB: be careful the mixture doesn't burn or catch on the base of the pan as this will ruin the sauce.)
Remove from the heat and allow to cool for a few minutes. Transfer to a food processor or liquidiser and blend until smooth. Push the sauce through a sieve into a bowl and allow to cool completely.
If you find the ketchup is too thin once cold, place into a pan and boil until thickened, stirring frequently. If necessary, add half a teaspoon of cornflour mixed to a paste with water; this will prevent the tomato water separating from the ketchup, but be careful not to make it to starchy and too thick.