Yummy Breakfast

I LOVE this kind of breakfast food - especially when company is in town.
Vegetable Cheese Strata
4 tsp olive oil
1 large onion, diced
3 cloves garlic, minced
8 oz white mushrooms, sliced
Cooking spray
1 whole wheat baguette, cubed (about 5 cups)
8 large eggs
8 large egg whites
2 cups nonfat milk
1 Tbsp Dijon mustard
10 oz frozen chopped broccoli, thawed
1/3 cup freshly grated Parmesan cheese
4 oz part-skim mozzarella cheese, shredded (1 cup)
1/2 cup thinly sliced sun-dried tomatoes (not oil-packed) soaked in hot water, then drained
1 Tbsp minced fresh thyme
1/2 tsp salt
1/2 tsp freshly ground pepper

Heat 2 tsp of the oil in a medium nonstick skillet over medium-high heat. Add the onion and cook, stirring, until softened and beginning to brown, 3-5 minutes. Add the garlic and continue to cook for 1 minute. Transfer the onion mixture to a medium bowl and let cool.
Heat the remaining 2 tsp of oil in the same skillet and cook the mushrooms stirring a few times until their water evaporates and they begin to brown, 5 to 7 minutes. Remove from the heat and let cool completely.
Coat a 9X13 baking dish with cooking spray. Arrange the bread cubes over the bottom. In a large bowl, beat the whole eggs, egg whites, milk, and mustard together until incorporated. Add the mushrooms, onion-garlic mixture, broccoli, both cheeses, the sun-dried tomatoes, thyme, salt, and pepper and stir to incorporate. Pour the mixture over the bread, making sure the liquid saturates the bread. Cover with plastic wrap and refrigerate overnight or at least 8 hours.
Preheat the oven to 350. Remove plastic wrap and bake until the top forms a light brown crust, 60-70 minutes.