Heat a 7.8-inch (20cm) ovenproof non-stick frying pan over medium heat, greased with the olive oil. Cook the sliced potato 5-6 minutes on each side or until lightly golden and tender. Transfer to a plate and set aside
Meanwhile, place the frozen peas in a bowl of hot water and allow to defrost until the peas are tender. Drain well.
Lightly whisk the eggs in a medium bowl. Season to taste with salt and pepper.
Preheat the grill on medium. Arrange half the potato at the base of the frying pan. Top with half the peas and half the goat’s cheese. Repeat the layering process once more and then pour over the eggs to cover the potato. Cook over a low-medium heat for 10 minutes or until the egg is almost set.
Place under the grill for 5 minutes, until the egg is just set on top. Cut the frittata into wedges, and serve with a handful of rocket.