Here's the only slow cooker recipe you need. Yes you brown the meat first and yes you finish with artificial thickener and yes it's hit onions but still, it's lush...
Get a piece of brisket just big enough to go in the pot and leave room at the sides
Brown it on all sides
Chop onions roughly and cover the bottom of the pot
Place brisket on top
Pack large chunks of carrot and large mushrooms around
Take a glass of red wine and add a stock cube and a squirt of tomato puree without other liquid
Add seasoning (no more salt). I like black pepper and ground chili and garlic
Tip wine mixture in
Lid on and cook (all day)
Lift out brisket and put on oven proof serving dish, lift out carrots and shrooms and arrange artistically. leave liquor and onions behind
Keep the meat and veg warm in low oven
Add thickener and browning to liquor & onions in pot (I like Coleman's squirty instant gravy which browns and thickens)
Use hand whizzer to make a thick onion gravy
Serve with jacket pots and greens...
... And beer (or wine)
Nom
[Edit for typo]