Cook shells according to packaged directions for al dente. Drain and place onto a paper towel to dry while you make the filling.
Place garlic into the bowl of a food processor and process until finely minced. Add ricotta, parmigiano cheese, eggs, salt, pepper and nutmeg and process until mixture is well blended, about 30 seconds. Add in well drained spinach and drained artichokes and pulse mixture until spinach and artichokes are broken down but not pureed, about 20-25 pulses, total.
Spread approximately 1/3 cup of crushed tomatoes onto the bottoms of two 9×9 freezer friendly, oven safe, baking dishes (I actually used 10-inch pie plates and as able to fit 16 shells in each). Note: use a bigger cooking vessel if you need one large batch and aren’t planning on freezing any for a later date—a 9×13-inch pan should work perfectly.
Fill each shell with approximately two heaping teaspoons of the spinach/artichoke mixture and place side by side into prepared baking dishes. Nestle them closely to each other until each of the to baking dishes are filled. Top the shells in each baking dish with remaining sauce and extra parmigiano cheese. Cover the one you plan on baking right away tightly with a piece of aluminum foil. Freeze the other batch according to instructions below.
Notes
To Freeze: Cover the batch you plan to freeze tightly with a layer or wax paper, then plastic wrap and finally a layer of heavy duty foil ( i like extra freezer burn insurance so i triple up!). Label the dish with a piece of masking tape and marker and don’t forget to include the date! This particular dish can be frozen for up to one month. Don’t forget to remove the waxed paper and plastic wrap and reseal with foil before placing into preheated oven. If baking shells from a frozen state, allow 60 minutes total cooking time.