How about this (you can substitute chicken breasts for the pork if you wish)
2 tsps olive or sunflower oil
4 medium pork steaks
1 onion finely chopped
9oz mixed mushrooms, sliced
4 tbsps dry white wine OR veg stock
1 tbsp whole-grain mustard
4 fl oz half-fat creme fraiche
2 tbsp chopped fresh tarragon OR 1 tsp dried tarragon
salt & freshly ground black pepper
Heat the oil in a fry pan, fry the pork for about 5 mins on each side or until browned and cooked through. Remove and keep warm. Add the onion and mushrooms to the pan and fry for 3 mins or until softened. Pour over the wine or stock, allow to bubble and reduce by half. Stir in the mustard, creme fraiche and tarragon. Season to taste.
Return the pork to the pan along with any juices. Bring to te boil, simmer 1 minute and serve.
I love it and it's quick and easy.