Place the red chilli, 2 quartered onions and all the peeled cloves from the head of garlic into a food processor or blender and whizz into a smooth slurry.
Heat the 2 tablespoons of vegetable oil in a large pan over a medium heat. Toss in the onion slurry and cook for 3-5 minutes until the mixture begins to take on some colour.
Now tip in all the spices (teaspoon of mustard powder, 1/2 teaspoon of turmeric, teaspoon black pepper, teaspoon of cumin, teaspoon of coriander, teaspoon of paprika and 2 teaspoons of sugar). Stir to combine with the onion slurry and cook for a further minute.
Pour in the can of chopped tomatoes, can of coconut milk,350g of halved sprouts and a teaspoon of sea salt. Stir to combine then bring the mixture to a rolling simmer. Cover and cook for 15-18 minutes or until the sprouts are fork soft.
Once cooked remove the pan from the heat and stir in the juice from the lemon. Serve immediately with a good helping of freshly prepared rice or a warm naan.