01 -
Bring a large pot of salted water to a boil. Cook the jumbo shells according to the package directions until they're al dente. Drain them and let them cool for a few minutes so you can handle them.
02 -
Heat a large oven-safe skillet (like a 12-inch cast iron) over medium-high heat. Add the ground beef and chopped onion. Season with salt, pepper, paprika, and Italian seasoning. Cook until the beef is browned, breaking it up as it cooks.
03 -
Drain off any excess grease from the beef. Add the minced garlic and stir for about 30 seconds. Pour in the jar of marinara sauce and let everything simmer on low heat while you prepare the filling.
04 -
In a bowl, mix together the ricotta cheese, egg, Parmesan cheese, garlic powder, and dried parsley. Stir everything together really well until it's smooth and combined.
05 -
Using a spoon, carefully fill each cooled shell with the ricotta mixture. Use about 1½ to 2 spoonfuls per shell. Not all the shells will be perfect - some might tear, so you won't use every single one. You'll need about 21 shells to fill a 12-inch skillet.
06 -
Place the filled shells in your skillet with the meat sauce, nestling them into the sauce opening side up. If you're not using an oven-safe skillet, transfer the meat sauce to a 9 by 13 inch baking dish first. Gently press the shells down into the sauce a bit.
07 -
Sprinkle the shredded mozzarella cheese evenly over the top of all the stuffed shells.
08 -
Bake at 400 degrees F for 25 minutes. You can bake it uncovered if you like crispy edges on the pasta and cheese, or cover with aluminum foil if you prefer everything soft.
09 -
Once the cheese is melted and bubbly, take it out of the oven. Sprinkle some dried parsley over the top for color. Let it cool for a few minutes before serving.