Whisk eggs and milk. Season with salt and pepper. Stir in peas. Heat oil in a pan (approx. 28 cm Ø). Pour egg mixture into the pan. Crumble the feta and spread on the omelette.
Allow to set in the preheated oven (electric cooker: 200 °C/ circulating air: 175 °C/ gas: level 3) for 10-15 minutes. Tear ham into small pieces. Arrange the omelette on a large plate, spread the ham on top.