cooking spray
5 large russet potatoes, halved and thinly sliced
salt and ground black pepper to taste
6 tablespoons butter
0.5 cup all-purpose flour
4 cups milk
4 tablespoons chopped garlic
1 (16 ounce) package shredded sharp Cheddar cheese
Step 1
Spray the slow cooker generously with cooking spray. Layer the sliced potatoes at the bottom of the slow cooker and season with salt and pepper. Repeat until all the potatoes are used up.
Step 2
In a saucepan over medium heat, melt the butter. Add the flour and whisk until bubbling. Cook, stirring constantly, for 1 to 2 minutes. Slowly add the milk and continue to cook, whisking continually, until thickened (5 to 10 minutes). Stir in the garlic.
Step 3
Remove from the heat and add the Cheddar cheese. Stir until the cheese has melted, placing it back on the heat briefly if necessary, being careful the mixture doesn't scorch. Pour the cheese sauce over the potatoes. Shake the slow cooker gently (do not stir!) to allow the cheese sauce to reach all the way to the bottom.
Step 4
Cook on Low for 8 hours or on High for 4 hours, until the potatoes are tender and fully cooked.