METHOD
STEP 1 : Heat the oil in a large deep frypan. Add the mustard seeds and cook over medium heat for 30 seconds or until they begin to pop. Add the onion and cook, stirring, for 3-4 minutes until softened. Stir in the tikka masala curry sauce and cook for 1 minute, then add the chicken and stir to coat in the paste mixture. Add the coconut milk and stock, then bring to a simmer and cook over low heat for 5 minutes, then add the zucchini and cook for a further 5 minutes or until the zucchini is tender and the chicken is cooked through. Season to taste with sea salt and freshly ground black pepper.
STEP 2 : Divide curry among plates and scatter with coriander. Serve with basmati rice.