Heat about 1 inch of olive oil in a large skillet over medium heat. Once hot, fry zucchini, in batches until golden, about 6-8 minutes. Doing this in batches is essential to get nicely golden zucchini. Place on a paper towel, sprinkle with salt, and set aside to drain.
Place a large pot of water over high heat for boiling the pasta. Preheat oven to 400ºF.
In a small bowl, mix ricotta, about ⅓ of the mozzarella, basil, parsley, and pecorino until combined. Fold in the drained zucchini. Season to taste with salt and pepper.
Once water is boiling, heavily salt your water and drop in the shells. Boil for 8 minutes (pasta will not be fully cooked).
Drain pasta and run under cold water to cool off. Drizzle with a touch of oil, so that the shells don't stick together.
Grease a medium-sized baking dish of any kind with a bit of olive oil.
Add a layer of marinara sauce to cover the bottom of the dish.
Fill each shell with ricotta mixture. Place shells in the prepared baking dish as you fill.
Top with an even layer of marinara sauce. **
Top with remaining mozzarella cheese, and a sprinkle of pecorino romano.
Cover with foil and bake for 40 minutes.
Uncover and broil until the cheese is golden. Garnish with fresh torn basil, if desired.
