Preheat the oven to 350°F. Line a medium baking sheet with parchment paper.

Make the turmeric cashews. Put the sugar, oil, turmeric, and 2 tablespoons of water into a small saucepan. Bring to a boil on medium heat, stirring often, then add the cashews and cumin. Cook for another 3 to 4 minutes, stirring constantly, until the seeds and nuts are coated in a sticky glaze. Transfer to the prepared baking sheet, using a spatula to spread the nuts out. Bake for 14 minutes, stirring once halfway, until golden. Set aside to cool completely.

Make the curry leaf oil by putting the chile and oil into a small frying pan. Place it on medium heat and cook for 7 minutes, or until the chile starts to develop a shine, then add the curry leaves and cook for 2 to 3 minutes more, stirring often, until the leaves turn translucent. Transfer to a bowl and set aside.

Make the dressing by putting the lime juice, mustard, garlic, poppy seeds, and ¼ teaspoon of salt into a small bowl and whisking to combine. Slowly drizzle in the olive oil, whisking continuously until incorporated.

In a large bowl, combine the cabbage, carrots, onion, ½ teaspoon of salt, and a good grind of pepper. Pour in the dressing, mixing well to combine, and let soften slightly, about 15 minutes. Fold in the cilantro and mint, then transfer to a large serving platter. Drizzle the curry leaf oil all over and sprinkle with a handful of the turmeric cashews, serving the rest in a bowl alongside, to munch on.