Cook the shells

• Bring a large pot of salted water to a boil.
• Cook the jumbo shells until al dente, then drain.

Brown the beef

• Heat the olive oil in a frying pan over medium heat.
• Add the ground beef, season with salt and pepper and cook until browned.

Make the filling

• Stir the marinara sauce into the browned beef.
• Add half of the mozzarella and the parmesan and mix until combined.

Fill the shells

• Spread a layer of the meat sauce in the baking dish.
• Spoon the filling into each shell and arrange them in the dish.
• Pour the remaining sauce over the top and scatter over the rest of the mozzarella.

Bake

• Bake until the cheese is melted and bubbling.