Pasta cooking in broth
Finished pasta with cheese - no egg yet
Grab a frying pan, fill it with water and put the cube in it, or use your broth. Cook your pasta/macaroni/whatever until it's ready, adding more water if needed.
Drain excess water if there is any in the pan. Add butter and fry the pasta until it is golden brown.
The order of the next two steps depends on how you like your cheese. If you like it soft and chewy, fry the egg first and then take the plate off the heat and add chese. Otherwise, add the cheese first, then the egg and fry the egg until it's ready. The cheese will grill a bit.
That's all there is to it!