Put the spaghetti in plenty of boiling salted water and cook for about 10 minutes until bubbly. In the meantime peel and finely dice the onion. Cut the bacon into fine cubes as well. Wash the thyme, dab dry and pluck off the leaves, except for a little to garnish.
Whisk eggs, cream, a little salt and pepper. Stir in cheese. Pour spaghetti into a sieve, rinse with cold water and drain. Heat oil in a pan and let the bacon in it crisp. Finally add onion and fry briefly.
Take out about 2 tablespoons of bacon and put the noodles in the pan. Add thyme and toss the spaghetti briefly in the pan. Pour egg and cheese cream over it and mix quickly with the spaghetti.
Season to taste with salt and pepper and immediately divide into 4 deep plates. Sprinkle with remaining bacon and serve garnished with thyme.