Step 1

Grease a 9 x 13-inch baking dish with butter.

Step 2

In a large nonstick skillet, melt 1 tablespoon of the butter over medium-high heat. Add the sausage and cook, stirring with a wooden spoon to break the meat into small clumps, until browned, about 10 minutes. Transfer the sausage to a large mixing bowl, leaving the fat in the pan.

Step 3

Turn the heat down to medium, then add the onions to the pan along with the remaining 1 tablespoon of butter. Cook the onions, stirring constantly, until soft and translucent, about 5 minutes. Add the onions to the mixing bowl with the sausage, along with the bread cubes, grated cheese, and parsley. Toss well, then spread the mixture evenly into the prepared baking pan.

Step 4

In a medium bowl, whisk together the eggs, half-and-half, salt, and pepper.

Step 5

Pour the egg mixture evenly over the bread mixture. Cover tightly with plastic wrap and refrigerate for at least 2 hours or overnight.

Step 6

Preheat the oven to 350°F and set an oven rack in the middle position. Bake for about one hour, uncovered, until puffed and golden brown. Slice into squares and serve immediately.

Step 7

Note: The cook time is based on cooking the bread pudding directly out of the refrigerator. If it's left to sit out at room temperature before baking, check for doneness after 45 minutes.