Preheat the oven at 190°C (375°F).
Cube the chicken breast, the zucchini, and the feta cheese.
Sauté the zucchini using 1 tbsp of the oil, in a frying pan, for about 5 minutes.
In a small cup, mix the remaining oil with the rosemary, salt and pepper.
Place the chicken bits in an oven cooking tray and coat well with the oil mix.
Layer the zucchini cubes over the chicken, then the feta.
Cover the tray with tinfoil and ensure the steam can escape (pierce the tinfoil in a few places).
Cook for approximately. 25 minutes and serve hot, with a bit of freshly squeezed lemon.