Bring a large pot of salted water to a boil over high heat. Add the penne pasta, cooking according to package instructions until al dente, about 10-12 minutes. Once done, reserve ½ cup of the pasta water for later use, then drain the pasta in a colander, shaking gently to remove excess moisture.

In a large skillet over medium heat, add the lean ground beef, breaking it apart with a spatula. Cook for about 5-7 minutes, stirring occasionally, until the beef is nicely browned and fully cooked with no pink remnants. If there’s too much fat, drain some off before proceeding to the next step.

To the skillet, add the diced onion and minced garlic, stirring well to combine. Sauté for about 2-3 minutes until the onion becomes translucent and the garlic is fragrant, being careful not to let it burn.

Stir in the tomato paste, mixing thoroughly with the beef mixture until fully incorporated. Pour in the beef broth and bring the mixture to a simmer over medium heat. Allow it to cook for about 3-5 minutes, allowing flavors to meld and the sauce to thicken slightly.

Reduce the heat to low and mix in the Greek yogurt and shredded cheddar cheese, stirring continuously until the cheese is melted and the sauce is smooth. If the sauce is too thick, gradually add the reserved pasta water until reaching your desired creaminess.

Gently fold in the cooked penne pasta into the creamy sauce, making sure each piece is well-coated. Toss everything together for about 1-2 minutes over low heat.

Transfer onto serving plates or bowls. Garnish with fresh chopped parsley and serve immediately.