How to Make It
Place sweet potatoes in a microwave-safe bowl with water. Cover with plastic wrap, and microwave at HIGH until tender, about 4 minutes. Remove plastic wrap, and set aside.
Melt butter in a large skillet over medium-high. Brown sausage in melted butter, stirring often, until sausage is browned and crumbled, 5 to 6 minutes.
Whisk together eggs, half-and-half, and Italian seasoning in a medium bowl. Stir together sausage, egg mixture, breadcrumbs, sweet potatoes, onion, and 1 cup of the cheese in a lightly greased 5-quart slow cooker. Sprinkle top with remaining 1 cup cheese.
Cover and cook on LOW until almost set, about 3 1/2 hours. Remove lid, and cook on LOW until edges are browned and liquid on top has evaporated, about 20 minutes. Garnish with fresh parsley.