Preheat the oven to 200C/400F/Gas Mark 6.
Get a bowl and put in the parsley, garlic, breadcrumbs and egg. Season with salt and pepper, add the feta cheese and mix up.
Open the sardine up from above, running the blade of the knife right along the spine, then slip a small knife under the bone in the belly to separate it. Take a couple of slices off the front of the fish so that they can be opened out more nicely.
Spoon the stuffing into the centre of the fish, then close the sardine back up and press it down. Tip out any excess filling into a bowl.
Season with salt and pepper.
Place on an oven rack and bake in a moderately hot oven for about 10 minutes.
Serving Suggestions: Serve with a bowl of lemon wedges.