Cover the beef chunks in the flour, brown that in a pot with the olive oil some salt and pepper (try not to brown it too much though)
Slightly brown the onion, garlic and carrot with it
Add a little stock to the bottom of pot and use a spatula to scrape out into slow cooker for extra flavour
Once that is added to slow cooker, add the rest of the stock and more pepper and a little more salt (how much seasoning is up to you) add the mushrooms and thyme and give a stir.
Cook for 6 hours on LOW
Once cooked, usually when meat is tender and carrots also, spoon some liquid from slow cooker, roughly a cups worth out into a small pot and heat up with the cornflour (stirring frequently until a little thick)
You can use a small sieve to put the thickening mix into slow cooker to help remove any clumps
Add spinach and stir through, and cook it for another 15-25 minutes.
I served this over a garlic mash (potatoes cooked with 2 cloves of garlic) and with buttered pane de casa bread, also can sprinkle a little fresh chopped flat leaf parsley on top as garnish.
Note: You can add more onion if you like, can also add more thyme, I did add probably about a tsp more of fresh thyme to the thickening mix while cooking it.