CAULIFLOWER & CHICKPEA TIKKA MASALA

1 medium cauliflower (about 1kg) • 2 tbsp vegetable oil • 400g can chickpeas, rinsed and drained • ½ tsp ground turmeric • 1 onion, finely chopped • 2 cloves garlic, finely chopped • 15g fresh root ginger, finely chopped • ½ x 283g jar Patak’s Tikka Masala Spice Paste • 200g fresh tomatoes, finely chopped • 3 tbsp non-dairy yogurt alternative, such as oat • ¼ x 25g pack coriander, leaves only • Steamed basmati rice, to serve