Hearty, but healthier breakfast/dinner casserole

Breakfast/Dinner Casserole with Turkey Sausage, Mushrooms, 
and Tomatoes Recipe

I found this recipe at Country Living.com and had to make it! This is a healthier casserole and I was very impressed by how yummy it was. Even though, the title was, "Breakfast Casserole," we had it for dinner this week. This is easy to prepare on a week night or for a Sunday brunch. We will be making this again for our family and friends!
*I made it with Swiss cheese instead and used only six slices of whole wheat bread (less carbs). For the full recipe, click here.

Ingredients

Olive-Oil Cooking Spray

14 ounce(s) Spicy Turkey Sausage, casings removed (I used reg. ground turkey and added chili flakes)

3/4 pound(s) Mixed Mushrooms (Such As Cremini, Shiitake, And Oyster), trimmed and sliced

Salt

Freshly Ground Pepper

1 small Onion, diced

8 slice(s) (large) Bread (4 Whole Wheat, 4 Hearty White), cut into 1-inch cubes - (I put six wheat slices).

5 ounce(s) Low-Fat Jarlsberg Cheese, finely grated (1 1/2 cups) 

1 pint(s) Grape Tomatoes, halved

5 large Eggs

5 large Egg Whites

1 1/2 cup(s) Low-Fat Milk

Directions

1. Coat a medium nonstick skillet with cooking spray and heat over medium heat. Add sausage and brown, breaking up with a wooden spoon as meat cooks, about 10 minutes. Using a slotted spoon, transfer sausage to a plate. Set aside.
2. Add mushrooms to skillet and cook over medium-high heat until they begin to brown, about 4 minutes, stirring occasionally. Season with salt and pepper. Add onion, reduce heat to medium-low, and cook, stirring occasionally, until onion is soft and mushrooms are well browned, about 4 more minutes. Set mixture aside.
3. Preheat oven to 350 degrees F. In a medium bowl, toss bread, cheese, tomatoes, reserved sausage, and reserved mushrooms and onions. Coat a 9- by 13-inch casserole dish with cooking spray and spread mixture in an even layer in dish. In a medium bowl, beat together eggs and egg whites. Whisk in milk and pour over bread mixture. Cover dish with aluminum foil and let casserole sit for 10 minutes. Press foil down gently to ensure top layer of bread cubes soaks up liquid.
4. Bake casserole for 35 minutes. Remove foil and bake 15 minutes more. Let rest for 15 minutes before serving.

Enjoy!