Preheat the oven to 350 degrees. And also preheat a large skillet over medium heat.
Add the olive oil to the pan, then add the onion and garlic. Saute for 3-4 minutes, until the onion starts to become translucent. Remove the pan from the heat, and add the spinach to wilt, stirring frequently.
Once it is slightly wilted, add the artichokes and season all of the vegetables with a pinch of salt and pepper.
In a large bowl, whisk the eggs, and season with a pinch of salt and pepper.
Spray a 9x13 inch baking dish with non-stick spray, and transfer the veggies to the pan. Spread the veggies out in an even layer, and sprinkle the cheese all over the veggies. Then pour all of the eggs over the top.
Bake for 30-35 minutes, until the eggs are cooked through and start to puff up a bit. Don't let them brown too much, it will dry them out.
Once cooked, remove from the oven and let cool slightly before cutting into it.