Preheat oven at 200C/180C fan/gas 6. Then wash and peel 4-5 carrots. Chop the carrots horizontally and set aside.
Wash and peel 4-5 parsnips. Then, chop the parsnips horizontally and set aside.
Wash 2 cups of Brussels sprouts and slice each one through the center.
Add all of the vegetables to a large bowl. Add salt to taste, pepper to taste, 1-2 tsp of thyme, 1-2 tbsp of vinegar, a splash of vegetable oil and mix.
Place vegetables on a tray, add 3 rosemary sprigs and 3 garlic cloves then bake for 30 minutes.