Pre-heat grill on medium, shelf in upper position, but not too close to the heat.
Break the eggs into a bowl, add the yogurt and beat together well, then season with salt and pepper.
Heat the oil in a shallow pan.
Add the spring onions and peppers, sauté for about 5 minutes until soft.
Add the kale, sauté everything for a further 2 minutes.
Pour the egg mixture into the pan and distribute it around to cover all the vegetables.
Cook the frittata without stirring until the bottom is firm and light brown. Do not allow to burn.
Remove the pan from the heat and sprinkle the parmesan cheese over the top.
Place the pan under the grill for 4 – 5 minutes until the frittata is golden brown.
Garnish with the parsley and then serve.