When cooked through, use a slotted spoon to remove the cooked chickpeas into a separate bowl to cool.
If you prefer to use the slow cooker, you can cook the soaked chickpeas in a slow cooker for 3-5 hours on a low setting, along with half an onion and enough liquid to cover the chickpeas by 2-3 inches. Reserve the yellow colored chickpea cooking liquid as this makes a great vegetable broth base for other dishes (this keeps in the fridge for a few days).
Any leftover cooked chickpeas can be stored in the refrigerator for a few days, to be used in different recipes. Often recipes with long cooking times will likely call for using uncooked (but soaked overnight) chickpeas, so be sure to check the recipe before cooking them.
Cooked chickpeas also freeze well in the freezer so you can make extra and just freeze a portion to take out later and thaw to use in another dish.