ROASTED TOMATO KETCHUP

Steps:

• Put the passata into a heavy pan with the vinegar, lemon juice, and spices. Bring to a simmer, then add the sugar. Stir until dissolved, then continue to simmer, stirring occasionally, for 25 to 30 minutes, until the sauce is reduced to a thick but pourable consistency.
• Pour immediately into warm, sterilized bottles or jars (see p. 152). Seal immediately with vinegar-proof lids (see p. 22). Store in a cool, dry place and use within 4 months. For longer keeping, sterilize the filled jars using the method on p. 125. Once opened, keep in the fridge.
• VARIATION
• Rhubarb makes a delightful fruity ketchup; this is a good way to use up the tougher, tarter stalks toward the end of the rhubarb season. Slow roast 4 1/2 pounds of chopped rhubarb with 9 ounces of chopped red onions and 3 or 4 garlic cloves at 350°F for about 1 hour. Strain through a sieve and put into a heavy saucepan. Use the same quantities of sugar and vinegar as above, but leave out the lemon juice (as rhubarb is very acidic). Replace the mustard, black pepper, and cloves with a good teaspoonful each of ground cumin and coriander. Continue to cook as for tomato ketchup.