Wash and clean the zucchini and cut them into slices about 1 cm thick. Peel onion and garlic and chop finely. Wash the rosemary, shake dry, remove the needles from the twigs and chop very finely. Coarsely grate cheese
Whisk eggs, milk and pesto. Season with rosemary, pepper and salt. Heat the oil in portions in an ovenproof pan (approx. 28 cm Ø). Fry the zucchini in the oil for approx. 4 minutes, turning them over. After about 2 minutes add onion and garlic to the last portion. Spread all the zucchini in the pan. Pour egg milk over the zucchini and sprinkle cheese on top
Allow to set in the preheated oven (electric cooker: 150 °C/ circulating air: 125 °C/ gas: level 1) for approx. 20 minutes. Remove the pan from the oven, let it rest for about 5 minutes and cut the frittata into cubes. Arrange on a plate and garnish with basil. Olives taste good with it
Waiting time approx. 5 minutes