4 to 6largepotatoesrusset are best, sliced ⅛-inch thick
210 oz. ham steakstrimmed of fat, bone removed, and cubed
salt and pepper
MAKE THE MUSHROOM SAUCE
In a large saucepan, heat the butter over medium-high heat.
Add the mushrooms and cook until starting to lose their liquid, about 5 to 8 minutes. As they are cooking, sprinkle with salt and pepper.
Add the flour and stir until the mushrooms are coated. Continue cooking for 3 to 4 minutes.
Whisk in the chicken stock and the cream. Continue whisking until all lumps have disappeared. Cook, stirring frequently, until slightly thickened. Stir in 1 tsp of salt, ½ tsp of pepper, and the Worcestershire sauce. Set aside until ready to use.
ASSEMBLE THE DISH
Add a layer of sliced potatoes in the bottom of the slow-cooker. To this, add a layer of the cheese, ham, and then onions. Season with salt and pepper.
Repeat this process until you've reached about 1 inch from the top of the slow-cooker.
Top with a layer of potatoes and cheese.
Spread the prepared mushroom sauce over the top. Sprinkle the smoked paprika over the top of the sauce.
Cook on HIGH for 4 to 5 hours, or on LOW for 8 to 9 hours.
The mushroom sauce can be made up to 2 days in advance. Keep stored in an air-tight container in the refrigerator. No need to re-heat when adding to the top of the casserole.You can prep all ingredients up to 1 day in advance. Keep the sliced potatoes covered in water and then drain and dry before assembling the casserole. Leftovers will keep in the refrigerator for up to 1 week and can be frozen for up to 2 months.