Ingredients:
- 3 lbs (1.36 kg) Yukon Gold potatoes, peeled and thinly sliced
- 1 medium yellow onion, thinly sliced
- 4 tbsp (57g) unsalted butter, melted
- 3 tbsp all-purpose flour
- 3 cups (720ml) whole milk
- 1 cup (240ml) heavy cream
- 1 tsp kosher salt
- 1/2 tsp black pepper
- 1/4 tsp garlic powder
- 1/8 tsp nutmeg
- 2 cups (225g) shredded sharp cheddar cheese, divided
Instructions:
- Peel and slice the potatoes and onions. Place sliced potatoes in a large bowl of cold water to prevent browning. Drain well before using.
- In a separate bowl, whisk together the melted butter and flour until smooth. Gradually whisk in the milk and cream until well combined. Add salt, pepper, garlic powder, and nutmeg (if using).
- Grease the slow cooker. Layer 1/3 of the potatoes, 1/3 of the onions, and 1/3 of the shredded cheese in the bottom of the slow cooker. Repeat the layers twice.
- Pour the milk and cream mixture evenly over the layered potatoes.
- Cover and cook on low for 4-6 hours, or on high for 2-3 hours, or until the potatoes are tender when pierced with a fork.
- During the last 30 minutes of cooking, sprinkle the remaining cheddar cheese over the top.
- Once cooked, let the scalloped potatoes rest for 10-15 minutes before serving. This helps the sauce thicken slightly.