Preheat oven to 220℃ / 425℉
In a mixing bowl, whisk together the egg, milk, cheese, herbs and seasoning (if adding).
Heat oil in a 10" cast iron skillet/pan over medium heat. Add the onion, garlic and bell pepper and cook for approx. 5 mins. Add the grated carrot and broccoli and cook for a further 1-2 minutes, or to desired softness. Stir in the peas.
Give your egg mixture a final whisk and pour the mixture over the vegetables. Stir briefly to distribute the mixture evenly across the pan.
Cook on the stove top, oven medium heat, for approx. 1-2 minutes. Just until the edges begin to set.
Transfer to the oven and bake for approx. 10-12 mins, until the middle has set.
Cool in the pan for 5 mins and then slice and serve.