First coat the pork medallions in the balsamic glaze (see recipe below for recipe) then sprinkle with half of the chopped chillies refrigerate for at least 30 minutes.
Pre heat the oven to 200°C.
Peel the onion, leaving the root end intact, then cut it into 6 - 8 wedges. Peel the shallots and slice them in half lengthways. Peel the garlic cloves and slice any larger ones in half lengthways.
Place all the veg (including the rest of the chilli and rosemary) in a roasting tray, spray with some Low calorie cooking spray and season.
Roast for 20 minutes. While the veg is cooking heat up a frying pan, then sear the pork medallions on both sides (about 2 minutes each side).
Pour in any remaining glaze, then transfer the pork into the tray with the roasting vegetables, return to the oven for another 10-15 minutes until the pork is cooked.
Put the balsamic vinegar and granulated sweetener in a pan and bring to the boil.
Allow to simmer until the balsamic has reduced by half and it coats the back of a spoon.
Remove from the heat and allow to cool. As the glaze cools it will start to thicken up even more, so if it starts to thicken too much just add a small amount of water and stir well. It needs to be the right consistency to coat things. You can store this in the fridge until you're ready to use it.