Preheat the oven to 210°C.

Clean the vegetables and peel the beetroot and onions.

Halve the onions and cut into thin strips (cut each half into 6 pieces). Peel the garlic, cut the cloves in half and press the cloves with the back of a knife.

Cut the beetroots into sticks (a bit like wedges).

Trim the ends of the fennel. Cut the bulb in half and remove part of the core if you wish, then chop the fennel into fine strips.

Cut the carrots into 2 or 3 lengthways, then cut the carrot pieces into sticks.

Cut the potatoes like wedges

Remove the zest from the orange using a zester and set aside. Cut the orange in half and squeeze the juice from half an orange.

Pour the orange juice into a very large bowl, add the zest, the olive oil and the rosemary. Add a pinch of salt and mix well.

Place the vegetables in the large bowl and toss with your hands to soak all the vegetables in the oil-orange-rosemary marinade.

Arrange the vegetables in a single layer on a baking tray lined with baking paper.

Place in the oven and stir the vegetables with a spatula halfway through cooking, after about 20 minutes.

Bake for a further 25 minutes, checking with a knife that the flesh of the vegetables has melted.

Season with pepper, set aside and reheat for a few minutes before serving!