Prepare the Tomatoes: Quarter the ripe tomatoes and blend them in batches until you have a smooth purée.
Pour the purée through a coarse sieve, pressing with a spoon to separate the juice and pulp from the skins.
Discard the skins.
Prep the Apples: Peel, core, and chop the apples into ½-inch / 1 cm chunks.
Simmer to Perfection: In a large, heavy-bottomed pot or enameled kettle, combine the tomato purée, chopped apples, chopped onions, cider vinegar, brown sugar, crushed mustard seeds, cayenne pepper, salt, ginger, and raisins.
Thicken and Develop Flavors: Bring the mixture to a boil, then reduce the heat to a gentle simmer.
Cook uncovered for about 1. 5 to 2 hours, stirring frequently to prevent sticking. The chutney is ready when it's thick, glossy, and a spoon dragged through the bottom leaves a clear trail.
Jar and Seal: Carefully spoon the hot chutney into hot, sterilized jars, leaving about ½-inch / 1 cm of headspace. Seal immediately and allow to cool completely before storing in a cool, dark place.
Let the chutney mature in the sealed jars for at least 2-4 weeks before opening. This allows the flavors to meld and deepen for a much richer taste.
Adjust the heat to your liking. For a milder chutney, omit the cayenne. For more warmth, add a cinnamon stick or a few whole cloves to the pot while simmering, removing them before jarring.