1. Begin by cooking the pasta according to the package instructions in a large pot of boiling salted water. Once it's al dente, drain it well and set it aside.
2. Next, heat the olive oil in a large skillet over medium-high heat. Add the ground beef and start breaking it apart with a wooden spoon. Cook until it’s browned, which should take about 3 to 5 minutes. Once cooked, drain any excess fat and set the beef aside.
3. In the same skillet, toss in the diced onion. Sauté for about 2 minutes, stirring frequently until it starts to become translucent. Then, add the minced garlic and cook until you can smell its fragrant aroma, around 1 minute.
4. Now, it's time to whisk in the flour. Stir continuously for about 1 minute, allowing it to get slightly browned.
5. Gradually whisk in the beef stock while mixing to combine. Then, add the marinara sauce along with the Italian seasoning, dried parsley, dried oregano, and smoked paprika. Bring everything to a gentle boil.
6. Once boiling, reduce the heat and let it simmer. Stir occasionally as it thickens, about 6 to 8 minutes.
7. After simmering, gently stir in your cooked pasta along with the reserved beef. Mix it well, allowing the pasta to soak up all those wonderful flavors.
8. Next, pour in the heavy cream and stir until heated through, which will take about 1 to 2 minutes. Taste it at this point and adjust the salt and pepper to your liking.
9. Now, add the sour cream into the mixture, stirring gently to combine.
10. Finally, fold in the freshly grated cheddar cheese until it’s melted and integrated into the mix. Serve it immediately, garnished with some parsley if you wish.