1. Preheat the oven to 180°C (350°F) on fan setting. Season the roast pork on all sides with salt and pepper. Rub the mustard all over the surface of the meat.
Using a sharp knife, pierce the meat. Insert garlic cloves and rosemary sprigs into the slits you made in the meat.
2. Place the meat in a roasting pan and pour in the wine and water. Cover the pan with non-stick parchment paper and aluminum foil, and roast the pork in the preheated oven for 2 hours. Uncover the pan and continue roasting for another 30 minutes or until the pork is nicely browned. Let it cool down and slice it.
3. Cut the small loaves of bread in half and place them in the sandwich press/toaster. Let them toast until golden brown, then spread with butter and add halloumi and roast pork slices. Grill a little longer in the press, then add cucumber and tomato.
If you like, serve with a few potato chips on the side.