Heat the oil in a skillet over medium heat. Add the onions, garlic, bell pepper, mushrooms, Italian herbs and salt. Cook for 3-5 minutes, until veggies are soft.
Add kale and sauté for an additional minute.
Place the veggie mixture in a mixing bowl, add the cheese and stir to combine. Allow to cool slightly.
Meanwhile, divide the pizza dough into 8 equal pieces (4 pieces per pound). Roll out each piece to a 6 inch circle.
Place about a 1/4 cup of filling onto center of the dough circles, fold them over to form half moons, and crimp the edges to seal.
Place the calzones on a parchment lined baking sheet and bake for 16-18 minutes, until golden brown.
Serve with pizza sauce on the side for dipping.
Notes
Storage: Allow to cool to room temperature, then store in an airtight container for up to 7 days in the refrigerator.Freezing: I love freezing calzones to have on hand for a quick weeknight dinner when you're low on time. You can freeze calzones before you bake them or after you baked them. To freeze them unbaked, flash freeze them on the baking sheet for an hour or so until they become more solid, then transfer to freezer bags.Reheating: No need to thaw or bring to room temperature. Just add about 5 minutes to the suggested cooking time and enjoy!I love having leftovers of this recipe because they're so good to have on hand for a quick weeknight dinner, and you can bake them straight out of the freezer!