- 6 tablespoons unsalted butter
- 3 tablespoons all-purpose flour
- 1 3⁄4 cups heavy cream
- 2 teaspoons dry mustard
- 1 1⁄2 teaspoons salt
- 1 teaspoon dried thyme leaves
- 1⁄2 teaspoon black pepper
- 2 baking potatoes, cut in half lengthwise, then in 1/4-inch slices crosswise
- 2 parsnips, cut into 1/4-inch slices
- 1 onion, chopped
- 2 cups shredded sharp cheddar cheese
Directions See How It's Made
- Slow Cooker Directions:.
- Melt butter in medium saucepan over medium-high heat. Add flour and whisk constantly 3 to 5 minutes. Slowly whisk in cream, mustard, salt, thyme, and pepper. Stir until smooth.
- Place potatoes, parsnips, and onion in slow cooker. Add cream sauce. Cover; cook on LOW for 7 hours or on HIGH 3 1/2 hours or until potatoes are tender. Stir in cheese. Cover until cheese melts.