cheddar and chive 24-hour omelet

0 Generously grease a 13x9-inch baking dish with butter. Spread the remaining 3 tablespoons of butter over one side of each bread slice. Cut the bread into 1-inch pieces. 
1 Arrange half the bread in the baking dish, then top with half the cheese. Repeat with the remaining bread and cheese. Set aside. 
2 In a large bowl, whisk the eggs, milk, and cottage cheese until combined. Add the onion, chives, salt, mustard, hot sauce, and several grinds black pepper and whisk to combine. 
3 Pour the egg mixture evenly over the bread (it's okay if some of the cottage cheese ends up sitting on top). If there are any pieces of bread that look dry, press down lightly to submerge. 
4 Wrap the dish in plastic wrap and refrigerate for at least 8 hours, and up to 24 hours. 
5 When you're ready to serve, heat the oven to 350°F. Unwrap the casserole and bake until puffed and golden brown, about 1 hour. Sprinkle with chives and serve warm, with hot sauce, if desired.