Zucchini Roll Ups (aka Zucchini Rollatini) are filled with a savory cheese mixture and topped with marinara sauce similar to stuffed shells but with just 10g net carbs per serving.
Trim the ends off the zucchini. Slice the skin lengthwise off one side, and then slice the skin lengthwise off the opposite side. Use a mandolin to slice the zucchini lengthwise into ¼ to ⅓-inch thick planks, or slice it by hand.
Lightly brush each zucchini plank with olive oil and sprinkle with salt and black pepper.
Grill or broil the zucchini planks for few minutes on each side until the zucchini is pliable, but not mushy. Cool.
For the Filling:
Heat the oil in a large, deep skillet over medium heat. Add the onion and cook until starting to soften, about 3 to 5 minutes, stirring occasionally. Add the garlic and greens and cook until the greens are wilted, about 1 to 2 minutes, stirring constantly.
Cool completely and then stir the greens mixture together with all remaining filling ingredients in a large bowl.
To Assemble and Cook the Zucchini Roll Ups:
Preheat the oven to 450F. Lightly brush the inside of a 9 by 13-inch casserole dish or two 8 by 8-inch casserole dishes with oil (or you can use 6 individual-sized gratin dishes).
Lay the zucchini strips on a large clean work surface. Spread a couple tablespoons of the filling on each, and then roll up. (Don’t worry about the rolls being perfect; this is a rustic homemade dish and they’ll still be delicious even if they aren’t perfect rolls.) Arrange the zucchini rolls in the prepared dish(es) and top with the marinara sauce and shredded mozzarella.
Bake until the cheese is melted and they’re warm throughout, about 10 to 15 minutes; serve.