Slow Cooker help please!!

[Chickadee]

I have got a beef stew simmering away but the liquid is much thinner than I would like.
I know that if I put cornflour in too early it will just cook out.
So if my stew will be served at about 6.30pm when is the best time to add the cornflour and should I leave it in low or turn it up to high?
Thanks.

[Im a BusyBee]

with all my gravy whether in the slow cooker or not (although it usually is!) i always use both cornflour and 'proper' bisto powder (not granules) 3 teaspoons each mixed with small amount of water and add to slow cooker before work when i first switch it on. If, when i get home about 4.30 i find it is not thick enough i then sprinkle some gravy granules in. They do need to be cooked for a further hour or 2 though or they do not dissolve properly.

[Chickadee]

Thanks Im a Busybee. I normally cover the meat in flour and find that enough for thickening, but I didn't today and that is why is too liquidy lol!!!
Will try the granules.

[Quizmonster]

Put a slosh of red wine in a cup, squeeze in a tablespoonful of tomato puree and two tablespoonsful of cornflour...stir and add to the pot at 6.10, turning the heat to 'High'. Should be great for 6.30!