Heat the olive oil in a large cast iron skillet over medium-high heat.
Add the chicken cubes to the skillet and cook for 5 minutes.
Add the onion and garlic to the skillet and cook for another 3 minutes.
Add the tomatoes, oregano, basil, red pepper flakes, salt, and black pepper to the skillet and stir to combine.
Reduce the heat to low and simmer for 10 minutes, stirring occasionally.
Stir in the parsley and cook for an additional 1 minute.
Serve the skillet chicken with tomatoes over your favorite sides.