Heat oil in a frypan over medium heat. Add tomatoes, basil, oregano, artichoke hearts and red capsicums. Cook until just hot then remove from heat. Transfer to a large bowl and toss with the mozzarella cubes.
Preheat oven to 180 degrees C. Lay out the pounded breasts and spoon filling onto the centre, leaving 2cm on each side. Adjust filling as you roll so as not to over stuff. Place them seam side down into a 2L baking dish. Cover with the tomato pasta sauce. Place lid onto dish or cover with aluminium foil.
Bake for 35 to 45 minutes in the preheated oven or until chicken is cooked through.