Place the tomatoes, cauliflower, onion, sugar, and 3 cups of vinegar into a large pot; bring to a boil. Reduce heat to medium-low and stir until the sugar has dissolved, 5 to 10 minutes.
Stir the flour, turmeric, mustard, curry, nutmeg, clove, and ginger together in a bowl. Stir in the remaining cup of vinegar to create a thin paste. Blend this mixture into the simmering tomatoes. Cook and stir until the mixture thickens, then simmer an additional 10 minutes. Cool completely and store in the refrigerator.