Preheat your oven to 180°C (fan-forced) and line a 20x30cm baking dish or slice tin with baking paper.
Grate the zucchini and carrot, then squeeze out excess moisture using a clean tea towel or muslin cloth.
In a large mixing bowl, whisk the eggs. Add the grated vegetables, onion, cheese, flour, oil and optional extras (if using), and mix to combine.
Season lightly with salt and pepper. Pour into your prepared tin and spread evenly.
Bake for 30–35 minutes or until golden and firm to touch.
Cool slightly before slicing into fingers or squares.