Making the Slow Cooker Sausage and Potato Casserole is a breeze when you follow these steps:

1. Prep the Slow Cooker: Lightly grease the slow cooker with cooking spray or olive oil to prevent sticking.
2. Layer the Ingredients: Start by placing the diced potatoes in the slow cooker, spreading them evenly across the bottom.
3. Add Sausage: Place the sliced sausage on top of the potatoes.
4. Add Onion: Spread the chopped onion over the sausage.
5. Mix Sauce: In a separate bowl, whisk together the cream of mushroom soup, milk, garlic powder, onion powder, salt, and pepper.
6. Combine and Pour: Pour the sauce mixture over the layered ingredients in the slow cooker.
7. Add Cheese: Sprinkle half of the shredded cheese on top of the sauce layer.
8. Cover and Cook: Secure the lid on your slow cooker and set it to cook on low for 6 to 8 hours or on high for 4 to 6 hours.
9. Final Touch: About 30 minutes before serving, add the remaining cheese on top and cover until melted.
10. Serve: Once the cooking time is complete, remove the lid, stir gently, and serve hot, garnished with chopped parsley if desired.

These straightforward steps will lead you to a delicious and fulfilling casserole that everyone will love.