Toast the pine nuts in a dry pan for a few minutes until lightly browned, then tip into a small bowl.
Add the feta, tomatoes, spinach & oregano to the bowl and mix well.
Slice a deep pocket into the slightly thicker edge of each chicken breast (be careful not to cut all the way through). Then stuff each with as much of the feta mixture as you can (push it right in so you can fit more in). Sprinkle each side of the chicken generously with salt and black pepper.
Heat up a couple of tablespoons of olive oil in a pan, then when it’s hot put the chicken in. Let it cook without moving it for about 5 minutes, then turn it over and cook for about another 5 minutes on the other side. Put a lid on the pan and cook for a few minutes longer until the chicken is cooked through (try not to overcook).
Transfer the chicken to a dish and keep warm, leaving any juices in the pan. Then add the chicken stock to the pan, scraping any sticky bits from the pan into it. Then squeeze in the lemon juice and add the butter, swirling it around until you have a silky gravy-like sauce. Continue to cook the sauce for a couple of minutes until it has thickened slightly.
To serve, cut each piece of chicken in half at an angle, or if you prefer slice it into three or four even slices. Serve with the sauce poured over the top and, if you like, a few leaves of basil scattered over.
Adapted from this recipe by Martha Stwart.I served this on top of mashed potatoes and baby broccoli. For a lighter meal, serve with roast potatoes or fries, crusty bread and a green salad or even with couscous, rice or quinoa. The side dish possibilities are endless!