Brown the ground beef in a large, deep skillet over medium heat. When it's almost cooked through add the taco seasoning, garlic powder, paprika, onion and green pepper and saute until the meat is finished cooking and the pepper and onion are soft.
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.
Once the liquid has almost completely reduced and the pasta is cooked to al dente, stir in the Greek yogurt.
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!