In a small bowl, whisk the two mustards with the grated lemon zest, pressed garlic, oregano/thyme and oil.
Spread the mustard mixture all over the pork. Rest for about 2 hours or refrigerate overnight.
Preheat the oven to 165°C.
Cut the zested lemon into thin rings - lay these in a roasting tin.
Put the pork on top, then pour in the wine. Season the pork with salt and pepper. Cover the tin with foil, then bake for an hour.
Take off the foil, turn up the heat to 180C degrees and roast for 20 minutes or so, until the glaze is golden.
Move the pork to a plate, cover and rest.
Remove the lemon bits from the tin, then reduce the jus to a gravy.
Carve the pork and serve with side dishes of your choice and the gravy.