Slow Cooked Brisket & Coriander Slaw

This is essentially my attempt to bring Grillstock home. We may not have the ridiculous barbecue apparatus (or the weather & wood chips for operating it) but we do have a slow cooker and access to CostCo's meat section.
Our beef had a not-so-successful earlier incarnation - after 8 hours of cooking (5 low, 3 high) it was definitely done (by sight and internal temperature) but was nothing like the tender falling-apart texture I was hoping for. We had some for supper anyway and it was pretty tasty with barbecue sauce (if a little tough), but it was the extra 12 hours overnight that turned the remaining beef into what we'd hoped for all along. I can't really give guidance on cooking time but for our 2kg rolled brisket it was definitely more than 8 hours and up to 20.
Tonight we ate the soft beef with leftover slaw on Tesco brioche burger buns. N had some Jack Daniels barbecue sauce on his - I didn't think it needed it as I'd reheated it in the juices/gravy/non-icky-accurate-word so I just added slaw to mine.

Pre-slaw

Brisket recipe:
Smashed together with reckless abandon from Tom Kerridge's Pulled Beef Brisket In A Milk Bun and BBC Good Food's Pulled Firecracker Brisket

Beef:
2kg rolled beef brisket, string removed, fat-side up

Under, at the bottom of the slow cooker:
olive oil, 2 red onions in thin slices, 6 cloves garlic, 2 red chillis with holes stabbed in them, splash of worcester sauce, generous splash of red wine vinegar, few drops lemon juice, star anise, dried coriander, dried marjoram, fresh-ish thyme
300ml good quality beef stock (we used a whole Knorr stock pot)

Beef - ready to go

On top, sprinkled and rubbed:
Smokey chipotle paste, double concentrate tomato paste
Coriander, cumin, mustard, cinnamon, cayenne pepper, fennel seeds, black pepper, brown sugar, sweet smoked paprika, paprika. Quantities roughly as reference recipes.


Cooking:
We did 5h on low, 3h on high, 1h dinnertime fiddling, 11h on low. Then I removed the beef from the pot and pulled it apart. We stored the beef in one tupperware and the liquid in another. These went in the fridge for ~10h, then we removed the layer of congealed fat from the liquid.

Serving:
For our sandwiches we reheated some beef in some of the liquid in a non-stick pan, then allowed the liquid to reduce to what would stay mostly inside a roll.

Before reheating

Coriander Slaw

Image shows leftovers, not full portion - be warned!

Prep time: 10 min
Cook time: 0 min
Total time: 10 min

Ingredients: 
Cabbage: half a small white one
Carrot: one large
Coriander: ~35g
Lemon juice: half a lemon's worth
Paprika: 1/2 tsp
Black onion seeds (nigella): 1 tsp
Greek yoghurt:100-150ml

Directions: 
1. Find a decent sized bowl - we used a 1L pyrex one after the prettier one turned out to be too small
2. Slice cabbage & carrot into small ribbons, preferably using a mandolin. Grating the carrot works but the result can be a bit mushy
3. Slice the coriander finely and put it in the bowl with the carrot and cabbage
4. Sprinkle on the black onion seeds and paprika, stirring about to spread them
5. Add lemon juice and stir
6. Add yoghurt gradually and stir until everything is nicely distributed, add enough to give a thin coating

Please excuse the giant heading  - I've attempted to use standard recipe markup so that Google, Pinterest etc will recognise this as a recipe.