Spray sides of slow cooker with non-stick cooking spray.
Mix all ingredients together in slow cooker until combined (see note).
Cook, covered, on high for 4 hours or on low 6-8 hours. Turn slow cooker to the warm setting to keep potatoes warm until you're ready to serve them.
If desired, reserve ½ cup of cheese. Fifteen minutes before serving, sprinkle reserved cheese on top, cover, and let cheese melt. This makes a nice cheesy topping for the potatoes.
To make a double batch, double all ingredients. Make sure you have a large enough slow cooker! Cook an additional hour.
Finely chopped onions (1 cup) can be added to the potatoes, if desired. More add ins: diced ham, crumbled bacon, cooked sausage, peppers.
Add a crispy cornflake topping (1/2 cup melted butter mixed with 1 1/2 cups cornflakes). Sprinkle the topping on for the last half hour of cooking time. I like to drape paper towels over the top of the crockpot, then put the lid back on so the condensation on the lid doesn't drip down and make the topping soggy.