Spray a 7 x 11" or 9 x 13" casserole dish with non-stick spray. Set aside. Preheat the oven to 375?F (191?C) if baking immediately.

In a large skillet over medium heat, brown the sausage. Spoon the browned sausage evenly into prepared casserole dish. Set aside.

Add a little olive oil to the same large skillet. Saut? the garlic, spinach, peppers, and onion until vegetables are tender and spinach is wilted, about 6-7 minutes. Season with salt and pepper during the last minute.

Remove from heat and add the cooked vegetable mixture to the sausage in the prepared casserole dish. Stir to distribute the mixture evenly. Set aside.

In a medium bowl, whisk together the eggs, milk, and ? cup of the shredded cheese. Pour the egg mixture evenly over the sausage and vegetable mixture. Sprinkle with the remaining ? cup of shredded cheese and a little more salt and pepper.

Bake the casserole for approximately 45 minutes or until the edges start to brown. Allow to cool for at least 15 minutes before serving. Store leftovers in the refrigerator for up to 5 days or freeze for up to 2 months.