Put all the ingredients apart from 1 tablespoon of the oil into a blender and whizz up until smooth. If it's a bit dry, and your blender is struggling, add a little water to loosen things up.
3 cloves garlic, 2 cm piece of ginger, 2 tablespoon cumin powder, 1 teaspoon black mustard seeds, 1 teaspoon turmeric powder, 4 tablespoon coriander powder, 1 red chilli, ¼ teaspoon cinnamon, 1 teaspoon black pepper, 1 teaspoon garam masala, ¼ cup vinegar, 4 tablespoon groundnut oil