Whisk 1 cup of thick plain yogurt in a bowl until smooth.
Put 1 packed cup of mint leaves, stalks removed, ½ cup of cilantro leaves and tender stems, 1 piece of ginger, ¼in / 5mm long, 1 small garlic clove, and 1 green chili in a blender.
Add ½ teaspoon of sugar, ½ teaspoon of salt, ½ teaspoon of roasted ground cumin, and a spoonful of the yogurt. Blend until fine.
Stir the paste into the rest of the yogurt. Taste and adjust the salt.
