Sweet Italian Sausage and Caramelized Onion Bread Pudding

Anyone who knows me knows about my love affair with caramelized onions. I could literally put them on anything and believe me, I have tried.

Sweet Italian Sausage and Caramelized Onion Bread Pudding

4 oz. sweet Italian Sausage links, about 3 links, casings removed and crumbled
5 or 6 small yellow onions, sliced
5 tablespoons unsalted butter
3 tablespoons olive oil
1 tablespoon balsamic vinegar
1 teaspoon sugar
1/2 teaspoon salt
8 - 1 oz. slices day old French bread, cubed
3/4 cup shredded sharp cheddar cheese
1/4 cup apple juice
1 large egg white
2 large eggs
1 1/3 cups half and half
1/4 teaspoon dry mustard
1/8 teaspoon salt

Heat the oil and butter in a large skillet over medium heat. Add the onions and cook, stirring for 15-20 minutes until very soft. Add sugar and salt. Lower heat to low and continue to cook for 40 minutes until golden, stirring occasionally. Stir in the vinegar and blend well.
Meanwhile, in a large bowl whisk together the half and half, dry mustard, salt, eggs and egg whites. Add the bread cubes and toss gently to coat. Let mixture stand for 20 minutes.
Preheat oven to 350 degrees.
In another small skillet, add the sausage and let brown for 10 minutes. Add the apple juice and cook until reduced to a glaze, about 15 minutes. Add the caramelized onions to the pan with the sausage and stir to combine. Add the sausage mixture to the bowl with the bread and sprinkle with the cheddar cheese. Stir again to combine. Spoon into a greased 8-inch square baking dish and bake for 40 minutes or until set and lightly browned. Let stand 10 minutes before serving.