Heat oven to 170C /150C fan/gas 4. Tip the beef stock, spices, garlic, passata and chilli paste (or tomato purée, if using) into a large flameproof casserole dish and season. Place on a medium heat, bring to a simmer, then add the beef and coat in the sauce. Cover and braise in the oven for 5-6 hrs, or until the beef is really tender. Remove from the oven and leave to rest for around 30 mins.
Using two forks, shred the beef into the sauce. Until this point, the dish can be prepared up to three days ahead – the flavours will improve over time. To reheat, stir in the beans and place on a low heat, then squeeze in the lime juice and keep warm on a low heat or in a low oven. Stir through the coriander just before serving.
To make the taco bowls, heat oven to 190C/170C fan/ gas 5. Brush each tortilla with a little oil, then tuck into a small ovenproof bowl or pudding basin and hold in place with a ball of foil. Cook for 8-12 mins until crisp. This can be done in batches if needed. If cooking ahead, leave to cool and keep in a large airtight container overnight. To serve, half-fill the tacos with the red cabbage & pickled chilli slaw, top with the chilli and sprinkle with your choice of toppings.
