Drain and dice the mozzarella. Cut blue cheese into cubes as well. Coarsely grate provolone and Parmesan cheese. Peel and finely dice the onion. Fry in hot oil. Pour on white wine and let it boil down a little.
Add cheese and let it melt while stirring. Stir in cream and bring to the boil once. Pluck the thyme leaves from the stems and add to the sauce. Season to taste with salt and pepper. Cook the pasta in boiling salted water for about 10 minutes and drain.
Serve with some sauce.