Blanch the peas in boiling water for 4-5 minutes, then drain. Preheat the grill to high. Beat together 2 eggs and half the milk. Stir in 1 tbsp shredded fresh mint and half the peas. Season with black pepper and a little salt (feta is quite salty).
Heat half the olive oil in a small omelette pan, then pour in the egg and pea mixture. Tip the pan and, using a spatula, move the mixture around to ensure it all cooks evenly. Cook for 4-5 minutes until the base is set.
Sprinkle over half the crumbled feta and place the pan under the grill until the omelette is bubbling and slightly golden.
Repeat with the remaining ingredients to make another omelette and serve the omelettes with a crisp, green salad.