Here's the recipe in case you can't find it or want to buy the cheaper generic shells.
1 box jumbo shells
1 lb ground beef
2 Tb olive oil
1 6 oz bag baby spinach, chopped
1 cup chopped onion
1 clove garlic, minced
1 tsp salt
1/4 tsp pepper
1/8 tsp nutmeg
1/4 cup Parmigiano cheese
1 jar tomato and basil sauce (I use any spaghetti sauce)
1 cup shredded mozzarella cheese
Cook shells and drain, reserving 1/3 cup of pasta water.
Cook ground beef until no longer pink. Drain grease.
Add oil, spinach, onion, garlic, reserved pasta water and continue to cook for 10 more min.
Remove from heat, add seasonings and let cool. Add egg and Parmigiano cheese. Stir to mix.
Pour 1 cup of tomato sauce into a 9X13 pan. Fill shells with meat mixture and place in pan. Pour remaining sauce over shells and sprinkle with mozzarella on top. Cover with foil and bake at 350 degrees for 30 minutes.