Preheat the oven to 425 degrees F.
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.