Remove the beef mixture from the skillet and add the diced tomatoes and beef stock to the hot skillet over high heat.
Add the pasta to the hot liquid and let the pasta cook as the liquid reduces. Stir every minute or so in order to promote even cooking.
Add the cheese and toss until the cheese is melted.
Add the meat mixture back into the skillet with the pasta, stirring to combine.
Garnish with some bits of chopped cilantro and a dollop of sour cream and serve it up in all its cheesy glory!