In a medium bowl, combine the ground beef, kosher salt, black pepper, and Italian seasoning or oregano, if you’re using it. Use a fork or clean hands and mix only until the seasonings are worked in. Don’t knead it to death. Overmixed beef can get dense, and nobody wants a zucchini boat packed with a meatloaf brick.
With clean hands, pinch off portions of the raw seasoned beef and press them into the zucchini channels. Fill them from end to end, pressing firmly enough that the beef holds together, and let it mound just a little above the zucchini edges. I do this directly in the baking dish whenever possible, mostly because I dislike washing a cutting board that has had raw beef on it. That’s not laziness; that’s wisdom earned the annoying way. For another easy option, see our Herb-Infused Baked Zucchini Fries with Almond Flour.
Pour the marinara all around and between the stuffed zucchini. Let a little run over the tops if you like. It will seem like there’s more sauce than necessary, but it keeps the zucchini moist and gives you plenty to spoon over everything later. Cover the dish tightly with foil.
