½ lime, scrubbed
2 cup (250 grams) frozen blackberries
¼ cup (50 grams) sugar
3 tablespoons low-sodium soy sauce
2 tablespoons honey
¾ teaspoon fine sea salt
½ teaspoon grated ginger or ginger paste or 2 teaspoons chopped fresh ginger
1 star anise
Pinch chili flakes
1 teaspoon (or a little more, to taste) rice vinegar
½ teaspoon (or a little more, to taste) sambal oelek (or other chili paste)
Finely grate the lime zest into a medium saucepan. Cut away the remaining peel and white pith to expose the fruit and then coarsely chop it. Scrape the fruit and whatever juice there is into the saucepan and stir in the rest of the ingredients (except the rice vinegar and the sambal oelek).
Place the pan over medium heat. Bring just to a boil, lower the heat to keep the ingredients at a steady simmer – and cook, stirring frequently, for 30 minutes. Remove the pan from the heat, then pick out and discard the star anise.
Purée the sauce using an immersion or stand blender, or food processor. Set a fine-mesh strainer over a bowl, scrape in the purée and, using a sturdy, flexible spatula, push it through the mesh. Discard the seeds that remain in the strainer.
Stir in the vinegar and sambal oelek, taste, and see if you’d like a little more of either. The sauce is ready to use now or it can be packed in a tightly covered container and kept in the refrigerator for up to 2 weeks.