Preheat your oven to 350 degrees F with a rack in the center position.
In a large ovenproof skillet, cook the bacon over medium-low heat until crisp, then transfer to a paper-towel lined plate to drain.
In the same skillet with the bacon fat, cook the diced potatoes until tender and browned, stirring occasionally.
Whisk together eggs, milk, Dijon mustard, salt, and pepper in a bowl. Mix in the shredded cheese.
Add the spinach and green onions to the skillet with the potatoes, stirring until wilted.
Spread the cooked bacon, potatoes, and greens in an even layer in the skillet.
Pour the egg mixture over the skillet contents, smoothing the top.
Bake in the preheated oven for 15 to 20 minutes until the eggs are set. Serve immediately.
DEVOUR!