Preheat your oven to 375°F and position the rack in the middle.
Heat olive oil in a 10-inch oven-safe skillet over medium heat, then sauté the diced onion and red peppers for 5-6 minutes until softened.
In a large bowl, whisk together the eggs, almond milk, garlic powder, salt, and pepper until well combined.
Stir the cooked quinoa and half of the cheese into the egg mixture, then pour everything into the skillet with the peppers and onions.
Sprinkle the remaining cheese on top and transfer the skillet to the oven.
Bake for 20-25 minutes until the center is set and the edges are lightly golden.
Remove from oven, let rest for 5 minutes, garnish with fresh parsley, and slice into wedges to serve.