Prepare Oven and Pan: Set your oven to preheat at 390°F (approximately 200°C). Lightly coat a large baking sheet with a portion of the olive oil (about 0.5 tablespoon).
Season Vegetables: On the prepared baking sheet, combine the sliced bell peppers and red onion. Sprinkle them with the ground cumin, Aleppo pepper, smoked paprika, half of the za’atar (about 2/3 teaspoon), and a pinch of kosher salt and freshly ground black pepper. Drizzle with the remaining olive oil (about 1 tablespoon) and toss everything together to ensure the vegetables are evenly coated. (Alternatively, you can mix these vegetables and seasonings in a separate bowl before spreading them on the pan). Add the fresh baby spinach to the pan, tossing lightly with the other vegetables; it will wilt down during cooking.
Roast Vegetables: Arrange the seasoned vegetables in a single layer on the baking sheet. Place in the preheated oven and roast until they are tender-crisp and show slight charring at the edges, typically for 12 to 18 minutes.
Create Nests and Add Eggs: Carefully remove the baking sheet from the oven. Using the back of a spoon, make four indentations amongst the roasted vegetables to serve as nests for the eggs. Gently crack one large egg into each nest, being careful to keep the yolk intact. (Helpful tip: Cracking each egg into a small ramekin or dish first, then carefully sliding it into its respective nest can help prevent broken yolks and ensure neat placement). Season the eggs lightly with an additional touch of salt and pepper if desired.
Bake Eggs to Preference: Return the baking sheet to the oven. Bake for an additional 6 to 9 minutes, or until the egg whites are fully set but the yolks have reached your desired level of runniness (less time for runnier yolks, more time for firmer yolks).
Garnish and Serve: Once the eggs are cooked to your liking, remove the baking sheet from the oven. Sprinkle the dish generously with the remaining za’atar (about 2/3 teaspoon), the freshly chopped parsley, and the diced Roma tomato. Serve immediately. This dish is excellent on its own or accompanied by a slice of whole-grain toast for a complete meal.