Heat the olive oil in a large skillet over medium-low heat.
Add the diced onion if using and cook for 4–5 minutes until softened.
Stir in the roasted peppers and diced tomatoes. Cook for 8–10 minutes, allowing the tomatoes to soften and release their juices.
Crumble the sirene cheese into the skillet and stir gently until partially melted.
In a separate bowl, lightly beat the eggs.
Pour the eggs into the skillet and cook over low heat, stirring gently until the eggs are just set but still creamy.
Remove the skillet from the heat before the eggs fully finish cooking. The residual heat will complete the process.
Season with black pepper and additional salt if needed.
Sprinkle with fresh parsley and serve immediately.