Cook the pasta in salted water according to the instructions on the package.
Meanwhile, dice the onions and sauté them in a pan in a little clarified butter until they are translucent to brown. Add tomato paste and roast a little.
Drain the pasta and add it to the pan as well. Mix everything briefly and season with salt, pepper and a little sugar. Scatter cheese on top and put the lid on. Don`t stir now! The noodles should be crispy from below and the cheese should melt at the top. Towards the end, coarsely pluck a few basil leaves and sprinkle over the pasta.