Peel the beetroot and cook for an hour. I had ready-cooked and vacuum-packed beets. Let the beets cool down and cut into pieces or, even better, grate them. Cut the garlic cloves into slices. Roast the pine nuts and set aside. Cook the spaghetti in salted water according to the instructions on the packet and drain.
Heat the olive oil in a large pan or in a wok and lightly roast the garlic. Add the beetroot and heat for 3 minutes. Add the cooked spaghetti, mix well and season with salt and pepper to taste. Warm up for another 5 minutes.
Serve the spaghetti on a plate. Sprinkle the crumbled feta cheese and the roasted pine nuts on top and garnish with basil leaves.