Peel and chop the onion. Fry in hot oil until transparent. Pour on wine and let it boil down a little. Cook pasta in boiling salted water for about 8 minutes. Stir mascarpone into the wine stock. Chop the nuts coarsely.
Peel and grate the carrots. Wash parsley, dab dry and chop. Add nuts, carrots and parsley to the sauce. Season to taste with salt and pepper. Drain the pasta, rinse with cold water and drain.
Arrange nests on plates, pour gravy over them.