These aren't your weeknight tacos. They could be, though, if you have a few hours to spare in the day. Otherwise, these slow-braised pockets of pork are here for your entertaining or special days fare. The beauty of this classic Mexican dish is how the braising liquid is served alongside for dunking the birria right into. Dip it like it's hot (which it is).
Preheat oven to 160°C fan-forced. Heat 2 teaspoons oil in a saucepan over medium heat. Add pork, season with ½ teaspoon salt flakes and pepper and cook, turning, for 5–6 minutes or until browned. Remove and set aside.
Finely chop onion. Peel and crush garlic. Add remaining oil, 3⁄4 of the onion (reserving remainder for salsa) and garlic to pan and cook for 4–5 minutes or until softened and caramelised. Add cumin and coriander blend and cook, stirring, for 30 seconds or until fragrant.
Dissolve stock cube in 500ml (2 cups) boiling water. Add stock, chipotle, 30ml (1½ tablespoons) red wine vinegar, sugar and tinned tomatoes to pan. Return pork and bring to a simmer. Cover with a lid and transfer to oven for 2½ hours or until pork is very tender. While pork is cooking, continue with step 4.
Finely chop tomatoes and coriander leaves. Place tomato, coriander, remaining onion and remaining vinegar in a bowl and season with salt and pepper. Thinly slice cabbage and place in a separate bowl. Season cabbage with a pinch of salt and pepper and massage with your hands. Cover both bowls and refrigerate until ready to serve.
Remove pork from braising liquid. Using two forks, shred meat. Place in a bowl with 60ml (¼ cup) braising liquid (reserving the rest to serve) and mix to combine.
Turn overhead grill to high. Divide cabbage and pork between tortillas and fold over to enclose, pressing flat. Place on a baking tray lined with foil. Brush tops with a little braising liquid and grill for 2–3 minutes or until golden. Serve tacos with salsa and small bowls of remaining braising liquid for dipping.