Season the beef steak pieces with salt, black pepper, garlic powder, and onion powder. Toss until evenly coated.
Layer the diced potatoes and onions at the bottom of the slow cooker. Add the seasoned steak pieces on top.
Sprinkle the corn over the steak layer.
Mix together the beef broth, heavy cream, and Worcestershire sauce. Pour this mixture over all layers in the slow cooker.
Cover and cook on low for 6–8 hours or high for 4–5 hours.
About 30 minutes before serving, sprinkle 1½ cups of shredded cheddar cheese on top and cover again.
Once cooked through, gently stir the casserole to combine everything. Taste and adjust seasoning if needed.
Top with additional shredded cheese and fresh parsley before serving.