4 baking potatoes
2 eggs, separated
120g (4oz) Cheddar or gruyère, grated
2tbsp chopped fresh chives
1 x 85g pack watercress, roughly chopped
2tsp Dijon mustard
Heat the oven to 200°C (gas mark 6). Bake the potatoes for 60 mins, then set aside until they are cool enough to handle. Cut the potatoes in half and scoop the flesh into a bowl, reserving the skins. Mix the potato flesh with the egg yolks, cheese, chives, watercress and Dijon mustard. Season with salt and pepper to taste.
Whisk the egg whites until stiff and gold them into the potato mixture to lighten it a little. Spoon the mixture back into the potato skins.
Return to the hot oven for 20 mins. Serve immediately.
You can make these ahead of time, up to the end of step 1.
This recipe originally appeared on House & Garden UK.