Warm the olive oil in a non-stick frying pan with an ovenproof handle and sauté the spring onions over a gentle heat for a few minutes until soft.
Add the watercress and stir gently until the watercress begins to wilt.
Remove the skin from the hot smoked salmon and flake it in pieces into the pan.
Add the lemon zest and dried chilli.
In a bowl, season the eggs generously with salt, black pepper and a pinch of nutmeg, add the crème fraîche and whisk until combined.
Pour into the pan and cook over a gentle heat, moving the mixture around with a spatula every now and then, until the bottom of the frittata is set and the top is still wobbly.
Scatter over the feta cheese, pop under the grill for another 2-3 mins to finish cooking the top, and serve.
Recipe by appetite magazine at https://www.appetitemag.co.uk/the-ultimate-power-breakfast-hot-smoked-salmon-watercress-frittata/