hi I'm sue Walker and I'm going to show you how to thicken stew in a slow cooker the things you will need are your hot stew some mash potato flakes or some corn starch a 1 table spoon measuring spoon and a whisk the easiest way to thicken stew and a slow cooker is to use instant mashed potato flakes you just add the flakes directly to the stew and stir until they dissolve add enough flakes until the gravy thickens to the desired consistency another way is to use corn starch and water this is better than flour because you won't get the lumps or the flour taste add 2 tablespoons of corn starch to 1 cup of water and mix until smooth add it gradually to the stew while stirring keep adding until you get the right thickness and that is how to thicken stew in a slow cooker