Bring large pot of salted water to boil. Add pasta shells and cook according to package directions until al dente, about 8-10 minutes. Drain and set aside.
While pasta cooks, heat large skillet over medium heat. Add ground beef, chopped onion, and minced garlic. Cook 6-8 minutes, breaking beef apart with spatula, until completely browned with no pink remaining. Drain excess fat.
Pour beef broth into skillet and stir in Italian seasoning. Simmer for 5 minutes to blend flavors and reduce broth slightly.
Stir heavy cream into beef mixture, mixing well until combined. Let simmer gently on low heat for 5 minutes until sauce thickens slightly and coats back of spoon.
Gently fold cooked pasta shells into creamy beef mixture, tossing until every shell is well coated. Taste and adjust seasoning with salt, pepper, or additional Italian seasoning if needed.
Transfer to serving bowls and serve hot. Garnish with extra Italian seasoning or grated Parmesan if desired.
Notes
Cook pasta al dente (slightly undercooked) as it will absorb some sauce and continue softening.
Use low-sodium broth to control salt levels since beef and cream add richness.
If sauce is too thick, add splash of pasta water or broth. If too thin, simmer uncovered a few more minutes.
Ground turkey or chicken work well as substitutes. Add olive oil when browning since they’re leaner.