Start by boiling water in a large pot. Once boiling, add a generous pinch of salt and the jumbo pasta shells. Cook according to package instructions until al dente. Drain and rinse under cold water to stop the cooking process.

In a large skillet, heat a tablespoon of olive oil over medium heat. Add the diced onion and minced garlic, simmering until the onion is translucent—around 3-5 minutes.

Add the ground beef to the skillet, breaking it apart with a spatula. Season with Italian seasoning, salt, and pepper. Continue to cook until the beef is browned, approximately 7-8 minutes. Drain excess fat.

Lower the heat and stir in the cream cheese until it melts and creates a creamy filling. Mix until fully combined, then gently fold in half of the shredded mozzarella.

Using a teaspoon, stuff each jumbo shell with the beef and cheese mixture.

In a 9×13 inch baking dish, spread 1 cup of marinara sauce evenly across the bottom. Place the stuffed shells on top, then cover with the remaining marinara sauce. Sprinkle the other half of the mozzarella cheese on top.

Cover the dish with aluminum foil and bake in a preheated oven at 350°F (175°C) for 30 minutes. Uncover for the last 10 minutes to melt the cheese beautifully.