This is such an easy pasta casserole! My recipe for stuffed jumbo pasta shells is made with ground beef, button mushrooms, and ricotta cheese; it all bakes together under a blanket of jarred marinara and mozzarella cheese. Dinner is ready in less than 1 hour!
Bring a large pot of salted water to a boil. Add in shells, cooking for 9 minute (we’re cooking them a little less than box time since we’re baking them in the oven next). Drain shells. Tip: Add 1 tablespoon of olive oil to the water while boiling the shells. This prevents the shells from sticking to each other.
In a large skillet over medium-high heat, cook ground beef until browned. Add mushrooms with ground beef and continue cooking until mushrooms are softened. During this time the mushrooms will release liquid. Once cooked, drain liquid and fat. Remove skillet from burner.
Add ricotta cheese, eggs, minced garlic, oregano and salt and pepper into the skillet, mixing to fully combine the ingredients together.
Add 1 cup of the marinara sauce to the bottom of a 9x13 baking dish, stirring around to fully coat.
Using a spoon, add in about 2 teaspoons of ground beef/mushroom mixture into each shell. Place the shells in the baking dish.
Spread remaining tomato sauce over the shells. Sprinkle the shells with mozzarella cheese.
Bake in the oven for 25 minutes, or until cheese melts and lightly browns. Serve and enjoy!