Halve the cherry tomatoes, and place them clustered together, cut side up, on a baking tray lined with paper.
Drizzle 1 tablespoon extra virgin olive oil and balsamic over the tomatoes, and season with salt and pepper. Place in a pre-heated oven to cook for 45 minutes, until tomato skins start to crinkle and the balsamic is caramelised.
Grate the zucchini, then sprinkle in salt and leave to drain for 30 minutes in a strainer. Rinse then squeeze out as much liquid as possible.
In an oven-proof frying pan, warm half the oil on medium-high heat. Add the prepared shredded zucchini and fry while stirring regularly for around 10 minutes, until the edges start to turn golden brown.
Add the prepared shredded zucchini and fry while stirring regularly for around 10 minutes, until the edges start to turn golden brown.
Meanwhile, in a separate bowl whisk together the eggs, then add the garlic, chilli, basil, chives, pecorino and salt and pepper to taste.
Add the cooked zucchini to the egg mixture and stir through.
Quickly wipe clean the frying pan then add the remaining oil. When the oil is hot and has covered the whole frying pan, add the egg mixture evenly and reduce the heat to medium-low. Top with the roasted cherry tomatoes, the cubed feta, and any other add-ins.
Allow the frittata to cook without stirring for around 10 minutes. Check the edges to see if the frittata is cooked underneath.
Once mostly cooked through, remove from the stove top and place the fry pan into the hot oven on the grill setting, or under the broiler, for a further 10 minutes.