Wrap the beetroot in foil, place on the oven rack and bake for 2 hours; set aside. Increase the oven temperature to 356 degrees F/180 degrees C. Place the onion and pumpkin on a baking sheet, drizzle over 2 tablespoons of extra-virgin olive oil and bake in the oven for 1 hour. Fifteen minutes before the pumpkin and onion are ready to remove from the oven, place the beetroot directly over the gas flame wrapped in foil and grill for 15 minutes.
Meanwhile, put the dried apricots in a medium pan, pour in the dark cherry balsamic vinegar and maple syrup and bring to a boil. Simmer for 15 minutes until the liquid has been absorbed by the apricots.
Heat 2 tablespoons of extra-virgin olive oil in a saute pan on low heat. Smash the garlic clove with a knife, add to the pan and gently saute for 4 to 5 minutes. Remove the garlic from the pan, add the chanterelle mushrooms and a pinch of salt, turn the heat up to medium high and saute for 5 minutes.
To another saute pan, add the almonds and toast for 3 to 4 minutes on medium-low heat. Then, add the sunflower seeds and a pinch of salt and cook for a further 2 to 3 minutes.
To assemble the dish, carefully remove the pumpkin from the skin and place on a serving plate or platter. Remove the onion from the skin and place on top. Peel back the foil from the beetroot, slice into pieces and add to the platter. Empty the apricots onto the board, roughly chop and sprinkle over. Place the almonds and sunflower seeds in a mortar and pestle, roughly grind and sprinkle over. Arrange the chanterelle mushrooms on top and around the vegetables and apricots. Pour over the balsamic vinegar. Finally, using a vegetable peeler or a truffle slicer, shave over the black truffle.