Place peeled and washed vegetables of your choice in oven bag
Add 2 tbsp of water into bag just to help steaming in bag
You could also add butter or garlic or herbs etc if you like
Add one cup of water to base of slow cooker
Twist oven bag closed at top but pierce in two places near top/twist
Sit bag (or bags - see below) in the shallow water of slow cooker with twist at top near the lid
Cover with slow cooker lid
Vegetables took approx 3.5hrs on high to reach tender
Open bag with care for hot steam
Notes
This method can be used to cook vegetables on the side of a main dish in another bag. Or two main dishes at once eg a less spicy main for children and a hotter one for adults, or just two dishes at once for serving various tastes in your dinner guests.
Bonus - next to no clean up!
Only use oven bags for this purpose, no other bags that are not suitable for cooking in.
Some (not most) slow cookers will specify not to use oven bags in them, so check your user manual first to be sure it's right for yours