1 thick pork fillet (120z/350g after trimming)
1 tsp English mustard
1 heaped tsp wholegrain mustard
1 heaped tsp Dijon mustard
4oz (110g) small open-cap mushrooms
7 fluid ounces (200ml) créme fraiche
1 dessert spoon groundnut or other flavourless oil
Half oz (10g) butter
1 small onion, halved and thinly sliced
3 fluid ounces (75ml) dry white wine
salt and frshly milled black pepper
You will also need a 9 inch (23cm) solid frying pan.

Trim the pork it and cut it into strips 3 inches (7.5cm) long and quarter inch (5mm) wide. Slice mushrooms through the stalk into thin slices.

In a small bowl, mix together the 3 mustards with the créme fraiche and, when you’re ready to cook the pork, take the frying pan and heat the oil and butter together over a medium heat. Add the onion slices and fry them gently for about 2-3 minutes until thery’re soft.

Using a draining spoon, remove the onions to a plate, turn the heat up under the pan to its highest stting and, when it’s smoking hot, add the strips of pork and fry them quickly, keeping them on the move all the time so they cook evenly, without burning. Then add the mushrooms and toss these around to cook very briefly until their juices start to run. Return the onion slices to the pan and stir them in. Season will with salt and pepper, then add the wine and let it bubble and reduce slightly before adding the mustard and créme fraiche mixture. Now stir the whole lot together and let the sauce bubble and reduce to half its original volume. Serve immediately, spooned over rice.