Peel and dice the onion. Fry in a little hot olive oil until translucent and add the milk (amount depending on the sauce requirements). Add half of the smoked cheese and melt in the milk. Season to taste with salt and pepper.
In the meantime, cook the spaghetti al dente according to the instructions on the packet.
Thicken the sauce with mondamin as needed. As soon as the spaghetti is done, add the remaining cheese cubes to the sauce (these are the bacon cubes - since the cheese has a brown edge on the outside, it actually looks similar) and serve immediately.
Serve with a green salad.
Note: In contrast to the original, this type of carbonara does not contain any cream or egg. The smoked cheese contains fewer calories than the bacon normally used. In contrast to the normal variant, you save a lot of calories.