Boil a large pot of water, add a generous pinch of salt, and cook pasta to al dente, according to package directions. Drain and set aside.
8-10 ounces medium pasta shells
While the pasta cooks, warm olive oil in a large skillet set over medium heat. Add the onion and sauté 2-3 minutes, just until softened.
2 teaspoons olive oil, 1/2 medium yellow onion
Add beef and cook 4-5 minutes, crumbling it into pieces, until nicely browned.
1 pound lean ground beef
Stir in chili powder, garlic powder, Italian seasoning, salt, and pepper, followed by the tomato sauce. Stir well and cook 3-4 minutes, until the sauce thickens slightly.
3/4 teaspoon chili powder, 1/2 teaspoon garlic powder, 1/2 teaspoon Italian seasoning, 1/4 teaspoon table salt, 10-12 cranks fresh-ground black pepper, 1 (15 ounce) can tomato sauce
Stir in the cream until warmed through, then add drained pasta shells. Stir well to combine, then serve with grated Parmesan and a sprinkling of fresh parsley, basil, or other herbs, as desired.
1/4 cup heavy cream, Parmesan and fresh herbs