01 - Preheat your oven to 350°F, positioning a rack in the middle.
02 - Heat 1 tablespoon olive oil in a 9-inch oven-safe nonstick skillet over medium heat. Add pancetta and cook for 3–4 minutes, stirring, until crisp. Remove pancetta with a slotted spoon and set aside, leaving the fat in the pan.
03 - Add the remaining 1 tablespoon olive oil, zucchini, and onion. Sauté for 5–6 minutes until the vegetables are soft and lightly golden.
04 - In a large bowl, whisk together eggs, milk, Parmesan, herbs, salt, and pepper.
05 - Stir the cooked pancetta into the zucchini-onion mixture. Pour the egg mixture evenly over the vegetables and pancetta in the skillet.
06 - Cook on the stovetop for 2–3 minutes until the edges begin to set.
07 - Transfer the skillet to the oven. Bake for 10–12 minutes, or until the frittata is puffed and just set in the center.
08 - Let cool for a few minutes, then slice into wedges and serve warm or at room temperature.