Spiced cauliflower

Name: Spiced cauliflower
Ingredients: 2 tbsp ghee or vegetable oil; 2 tsp chilli powder; 2 tsp ground cumin; 2 tsp ground coriander; 2 tsp turmeric; 2 tsp ground black pepper; 1 cauliflower, broken into small florets; 25g/1oz tamarind paste (optional); 250ml/9fl oz boiling water; 1 tbsp vinegar; Salt