Preheat your oven to 400 degrees f. and line a large baking sheet pan with parchment paper.
On your prepared sheet pan, add the mushrooms, sausage, peppers, red onion, then sprinkle everything with garlic powder and Italian seasoning.
Drizzle with 1 tablespoon of your oil and toss well to evenly coat everything.
Arrange in a single layer and roast for 13-15 minutes, or until veggies are tender and sausage is goldenbrown and hot.
Meanwhile, in a large bowl, whisk the eggs together with your milk of choice, mustard powder, and a pinch of sea salt and pepper.
Preheat a large skillet and drizzle with your remaining tablespoon of oil.
Add the beaten eggs and cook until just scrambled.
Once the veggies and sausage are finished roasting, remove them from the oven. Top
with your scrambled eggs (evenly distributed throughout) and shredded cheese.
Return sheet pan to the oven for 3-5 minutes more, just until the cheese is nice and melty.
Sprinkle with chopped parsley or chives and serve while hot.
Enjoy!