Grease a 9x13 baking pan Slice the baguette then quarter each slice and set aside. Brown pork sausage in a heavy skillet. Use a spoon to break up the meat into small pieces. Once browned put the meat into a medium size bowl and set aside. The add 2 tbsp of olive oil to the pan and sauté the onion until translucent about 5-7 minutes. Then add the cooked onion to the bowl with the cooked pork.
Add 2 tbsp of olive oil into the pan and cook the mushrooms and add about 1/4 tsp of salt and cook for 5-7 minutes. Transfer the cooked mushrooms to the bowl.
Add 2 tbsp of olive oil to the pan once again and then add the spinach long with 2 tsp of salt and cook down until wilted. Take out of the pan and cut into small bite size pieces and add the spinach to the bowl.
In a large another bowl add all the eggs and whisk them together add the half-half and whisk together. Add salt and pepper and whisk.
Pack the bottom of the baking dish with the cubed bread making a single layer. Add a layer of the sausage/mushroom/onion mixture. Then a layer of cheese. Repeat until the sausage mixture is gone from the bowl. Finish with a layer of cheese as your last layer on the top of the egg dish.Slowly, pour the egg mixture carefully over the whole pan of bread, sausage and cheese mixture. Cover with foil and place in the refrigerator over night!! When ready to bake preheat oven to 325°Keep the Strata covered and bake for 30 minutes, uncover the strata and bake another hour. Bake until the dish is brown and bubbling. Let cool for 15 minutes then cut into large pieces.HAPPY EATING!!