Bacon and Egg Carbonara

1. In a wide fry pan; cook bacon over medium heat until crisp.
2. Spoon off and discard all but 3 tb of the drippings; keep pan with bacon warm over lowest heat.
3. In a 5-6 quart pan; cook pasta in three quarts boiling water just until tender to bite, according to package directions.
4. After adding the pasta to the boiling water, spoon 1/2 c of the sour cream into each of 4 wide, shallow bowls; place bowls in a 200 degree oven while completing cooking.
5. Drain pasta well; add pasta and chives to bacon in the pan. Mixi lightly, using two forks.
6. Spoon an equal portion of pasta mixture into each warm bowl.
7. Make a nest in the center of each; slip in an egg yolk.
8. Mix each portion individually and sprinkle with cheese.