Beat eggs, cold water and mint leaves in a bowl until combined. Season with salt and pepper. Preheat grill on high.
Heat a medium frying pan over medium-high heat until just warm. Add butter. Tilt pan back and forth until butter sizzles.
Beat eggs again. Pour into pan. Tilt pan so eggs cover base. Using a wooden spoon, drag cooked egg from outer edge into centre. Tilt pan so uncooked egg comes into contact with base.
Meanwhile, cook peas in a saucepan of boiling water for 2 minutes. Drain.
Sprinkle peas over omelette. Dollop with cottage cheese. Place pan under grill. Cook until omelette is set. Cut omelettes in half. Slide onto plates. Serve.
