Cauliflower curry with Keralan lemon rice

Ingredients

• 2tbsp sunflower oil
• 2 red onions, sliced
• 2tbsp garam masala
• 1tsp chilli powder
• 1tsp kalonji (black cumin) seeds
• 1 tsp turmeric
• 400 ml can coconut milk
• 400 g can chopped tomatoes
• 1 large head cauliflower, cut into florets
• Juice 1 lemon
• Coriander leaves, to serve
• For The Lemon Rice:
• 200 g basmati rice, rinsed
• Zest and juice 1 lemon