Pre-heat the oven to to 180°C, fan 160°C, gas 4. Place the sweet potatoes, onions, beetroot and rosemary into a large roasting tray. Drizzle over 2 tbsp oil and place in the oven for 20-30 mins. Or until cooked through
Meanwhile, make the dressing. Put the red wine vinegar, ½ tbsp. olive oil, Dijon mustard into a small jar or bowl and mix. Set aside.
In a large frying pan, add the chorizo slices and cook for 2- 3 minutes or until cooked and golden. Remove and set aside.
When the vegetables are roasted, remove from the oven and cool. Get a large bowl. Mix together the roasted vegetables, salad leaves and chorizo and sprinkle over the walnuts. Serve with the salad dressing.