Oven should be preheated to 400°F (200°C) and an oven-safe skillet or round baking dish should be lightly greased with olive oil.
Grate the zucchini and carrot with a box grater.
Put the grated zucchini into a clean kitchen towel and squeeze it firmly in order to get as much of the excess moisture as possible out of it. This will allow the frittata to set properly.
Put the eggs into a big mixing bowl and whisk them until they are smooth.
Grate the zucchini, add the carrot, the chopped onion, the minced garlic, the mozzarella, the Parmesan, the Italian seasoning, the garlic powder, the paprika, the salt, and the black pepper.
Stir all the ingredients well until the vegetables and the cheese are evenly scattered throughout the egg mixture.
Put the mixture into the skillet or baking dish that has been prepared and use a spatula to spread it out evenly.
If you want, place the halved cherry tomatoes on top and then sprinkle them with a little extra mozzarella.
Bake it for 20 to 25 minutes, or until the centre has set, the eggs are fully cooked and the top has turned a slight golden colour.
If you want a richer golden colour to the cheese topping, broil it for an extra 1 to 2 minutes making sure to watch it closely so that it doesn't burn.
Take the frittata out of the oven and let it stand for five minutes until it has set before cutting it.
Add fresh parsley that has been cut into pizza-style wedges and serve it warm.