Before You Begin:
Prepare your slow cooker and ingredients as needed. Cooking times may vary depending on your slow cooker and ingredient thickness.
Slice potatoes evenly and pat completely dry.
Grease the inside of the slow cooker with butter.
Stir heavy cream, cheddar, Parmesan, garlic, salt, and pepper in a bowl.
Layer potatoes and sauce in the slow cooker, ending with sauce on top.
Cover and cook on LOW for 4–5 hours, or until the potatoes are tender when pierced with a fork.
Add extra cheddar during the last 30 minutes if you want a melted top.
Serve warm directly from the slow cooker.
Cooking NotesServes about 6–8 people, depending on portion size.Prep time is approximately 20 minutes.Cook on LOW for 4–5 hours until potatoes are fork-tender.Total time ranges from 4 hours 20 minutes to 5 hours 20 minutes.Once done, the dish can stay on WARM for up to 1 hour before serving.