To cook the bacon: Place the bacon in a large saucepan along with the bay leaf, peppercorns and onion and cover with cold water. Cover the saucepan and bring to the boil. Reduce the heat and gently simmer for about 45 minutes.
To make the glaze and yogurt dressing: In a small bowl mix all the glaze ingredients together. Season and taste. Take a tablespoon of the glaze and add it to the yogurt along with some chopped parsley. Store in the fridge while you finish cooking the bacon.
Preheat the oven the Gas Mark 4, 180°C (350°F).
To roast the vegetables: Toss the carrots, parsnips and onions in a tablespoon of olive oil. Season with a little salt and black pepper. Place in a roasting tin and pop in the oven. Roast for approximately 20 minutes until cooked.
When the bacon is cooked remove it from the water and place in a baking dish lined with parchment paper or tin foil. Allow to cool a little. Keep the cooking liquid to add to soups but discard the flavourings. Remove the rind from the bacon and discard. Brush the bacon liberally with half the glaze. Place in the oven and bake for 20 minutes. After 10 minutes brush over the remaining glaze.
To prepare the couscous: Place the couscous in a large bowl. Stir through the lemon juice, olive oil, garlic and 200mls of boiling water. Cover and leave for 10 minutes.
When the bacon is golden remove it from the oven. The vegetables should also be cooked at this stage. Allow the bacon to rest for a couple of minutes while you finish off the couscous.
Stir the roasted vegetables through the couscous. Taste and season. Transfer to a serving dish.