Cauliflower and pea curry

Name: Cauliflower and pea curry
Prep time: 10 min
Cook time: 20 min
Total time: 30 min
Cuisine: Indian
Ingredients: 1 extra-large cauliflower, leaves and stalk discarded, cut into florets; 3 tbsp vegetable oil; 2 tsp garam masala; 1 large onion, finely sliced; 3cm piece ginger, finely chopped; 1 chilli, deseeded and finely chopped; 2 tsp cumin seeds; 2 tsp ground coriander; 1½ tsp ground turmeric; 400g tin chopped tomatoes; 1 vegetable stock pot, made up to 300ml; 150g frozen peas; ½ lemon, juiced; 5g coriander, leaves picked; basmati rice and natural yogurt, to serve (optional)