Preheat the oven to 180°C (conventional) or 160°C (fan-forced).
Lightly grease one medium-sized oven-proof dish.
Heat the oil in a large pot over a medium heat, and fry the garlic and onion by stirring constantly until they become soft.
Add all grated vegetables to the pot and fry them over medium-high heat for 10 minutes (or until they start to soften). Drain off any excess liquid, and allow the vegetables to cool for approximately 10 minutes.
In a large bowl, whisk the eggs, flour, and AdVital Powder until the mixture is smooth. Add the milk, and whisk it until it becomes smooth.
Add the vegetables to the mixture and stir them through. Season to taste, and pour the mixture into the previously prepared dish.
Sprinkle grated cheese evenly over the top.
Place the dish in the oven and bake it for approximately 60–75 minutes (or until firm, golden, and slightly puffed).
Leave it to stand for approximately 5 minutes before serving.