Cook the tagliatelle pasta according to the package instructions.
In a large saucepan, heat the olive oil over medium heat. Add the carrots, celery, and onions and sauté for about 3 minutes until just tender.
Add the ground beef and cook until browned, stirring the meat to break it up.
Pour in the marinara sauce along with the salt and pepper and simmer for about 30 minutes, stirring occasionally, until the sauce thickens.
When the sauce has reached the desired consistency, stir in the heavy cream.
Remove from heat, and serve over cooked tagliatelle. Top with freshly grated parmesan cheese. Enjoy!