01 - Preheat the oven to 375°F.
02 - Heat olive oil in an oven-safe, nonstick skillet over medium heat.
03 - Add pancetta and cook for 3–4 minutes until golden and crisp. Remove and set aside, leaving the fat in the pan.
04 - Add onion and zucchini to the pan. Sauté for 5–7 minutes until soft and lightly golden.
05 - In a large bowl, whisk together eggs, milk, Parmesan, salt, and pepper. Stir in parsley and chives.
06 - Return pancetta to the skillet, spreading it evenly with the vegetables. Pour the egg mixture over the vegetables and pancetta, gently stirring to distribute evenly.
07 - Cook on the stove for 2–3 minutes until edges begin to set.
08 - Transfer skillet to the oven and bake for 10–12 minutes, or until the frittata is set in the center and lightly golden.
09 - Remove from oven, let rest for 2 minutes, then slice and serve warm or at room temperature.