01 -
Preheat oven to 175°C.
02 -
In a large oven-safe skillet over medium heat, add olive oil and sliced onions. Sprinkle with half the salt and cook, stirring occasionally, until onions are deeply golden and caramelized, about 15-20 minutes.
03 -
In a mixing bowl, whisk together eggs, remaining salt, black pepper, and fresh herbs until well combined.
04 -
Pour the egg mixture evenly over caramelized onions in the skillet, gently stirring to distribute the onions throughout.
05 -
Transfer the skillet to the oven and bake for 20-25 minutes, or until the frittata is set yet still slightly tender in the center.
06 -
Allow to cool briefly before slicing. Serve warm for optimal flavor and texture.