Set your oven temperature to 180°C (350°F) to warm up while you prep.
Prepare an 8-inch square baking dish by lightly greasing it and lining with parchment paper.
In a big mixing bowl, toss together the grated zucchini and carrot, then press out any extra liquid using your hands or a clean cloth.
Add in the finely chopped onion, minced garlic, and herbs if you decide to include them.
In another bowl, beat the eggs together with the olive oil and grated cheddar cheese until smooth.
Combine the egg mixture with the vegetables and stir well to coat everything evenly.
Slowly fold the self-raising flour into the mix, stirring just until everything is combined, then season with salt and pepper.
Transfer the batter into the lined pan, smoothing it out into an even layer.
Put the pan into the preheated oven and bake for about 30 to 35 minutes, until the top is golden and the center feels firm.
Take the slice out of the oven and let it cool down a bit in the pan before cutting it into squares or your preferred shapes.
Enjoy warm or cooled to room temperature as a satisfying meal or snack.