Ricotta and Spinach Stuffed Shells

1. Preheat oven to 350F and spray a 9x13 baking dish or casserole dish with cooking spray; set aside. Tip - I prefer a ceramic or porcelain baking dish as opposed to a standard 9x13-inch metal pan, although it will work, noting baking time may be slightly reduced.

Shells

1. To a large pot, add water, bring to a boil, and cook the shells according to package directions for al dente. Likely about 10 to 12 minutes. When they're finished, drain, rinse with cold water, optionally (but recommended) drizzle them with a bit of olive oil so they don't stick, and set aside. While shells are boiling, prep the spinach.

Spinach

1. To a large skillet, add the olive oil, garlic, spinach, and saute over medium heat for about 4 minutes, or until spinach has wilted and garlic is fragrant; stir nearly constantly so the garlic doesn't burn.
2. Turn off the heat, place the skillet on an unused/cool burner, and let the spinach mixture cool for about 5 minutes. When it is cool enough to handle, using paper towels, squeeze out the excess moisture.
3. Place the spinach on a cutting board and finely chop it.

Filling Mixture

1. Place the spinach in a large bowl along with the ricotta, Parmesan, egg, salt, pepper, parsley, basil, oregano, and stir to combine. Taste and if desired, adjust the seasoning balance, adding more salt, pepper, or herbs as desired. Tip - If you have fresh herbs on hand, feel free to use them rather than dried. I suggest about 1 1/2 teaspoons of fresh herbs if you are replacing 1/2 teaspoon dried (which is more concentrated and potent).

Assembly

1. Add about 3-4 tablespoons of marinara sauce to the bottom of the prepared baking dish and smooth to create an thin layer of sauce. Tip - You can use store bought sauce or your favorite homemade marinara or bolognese sauce.
2. Fill each jumbo shell with about 1 1/2 tablespoons of the ricotta mixture, placing each filled shell in the prepared pan, until all shells have been filled.
3. Evenly pour about 2+ cups of the marinara sauce over the shells. Note - You may or may not use all 24 ounces of sauce (2 1/2 cups = 20 ounces sauce, plus a few ounces used in the base of the baking dish), but you'll likely come close. It also depends how saucy you like things, so add to taste.
4. Evenly sprinkle the mozzarella cheese over the top. If you plan to bake now, skip the Making In Advance section, and just move on to baking.

Making In Advance

1. If you are prepping this in advance (up to 24-48 hours) before you plan to bake it, stop now, cover tightly with foil, and refrigerate. You can also freeze this, assembled, before baking it off, noting you need enough space in your freezer to accomodate a casserole dish. You can also carefully freeze the stuffed shells in a large ziptop freezer bag, without adding the sauce and mozzarella, just the stuffed shells. This requires less storage space since you're dealing with a bag of shells, not a rigid casserole dish.

Baking

1. Bake for about 30 minutes on the center rack, or until the edges are bubbling, and the cheese is as lightly golden browned as desired. Rotate your pan once midway through baking for the most evenly baked shells. Note - If you refrigerated your casserole dish with the assembled shells, marinara sauce and cheese over the shells as a make-ahead option, make sure to take it out of the fridge 30-45 minutes before you plan to bake and let it sit on your counter because a very cold baking/casserole dish will add a lot of unnecessary time to the baking process. If you froze it, thaw thoroughly before baking.

Storage

1. Leftover shells will keep airtight in the fridge for up to 5 days, or in the freezer for up to 3 months. Reheat gently in the microwave for about 30-60 seconds, or as desired.