To make the paste: Combine the coriander seeds, peppercorns, Kashmiri chillies, cassia bark, cumin seeds, star anise, cloves, cardamom seeds and cornmeal in a dry frying pan.
Gently toast the spices on a low heat, moving around constantly until aromatic (3-5 minutes). Don’t let the spices catch and scorch.
Place the dry-roasted spices in a pestle and mortar or in a small blender and grind to a fine powder.
Add the tomato puree, sugar, salt, lemon juice, garlic, yoghurt and ginger and blend again until smooth. Add 3-5 tbsp water if needed.
Bring a pan of salted water to the boil and add the cubed paneer and tofu. Gently boil for 4 minutes and drain. This softens them up for the marinade.
Combine the paneer and tofu, along with the cassava (or potatoes) and mushrooms with the tandoori paste and combine gently. Refrigerate for 1 hour-24 hours depending on the time you have.
Skewer the ingredients onto metal skewers or soaked wooden skewers and place over hot coals, turning until deliciously charred.