Cut up the chicken into bite sized pieces and season with salt, pepper, and garlic powder.
Place a large skillet over medium heat, add one turn of the pan of olive oil. Add in the diced red pepper, chopped onion, and minced garlic. Saute until the onions are translucent.
Add the chicken to the pan and cook until no longer pink.
Pour in the marinara sauce, chicken stock, and Italian seasoning and mix to combine.
Add in the pasta pushing the noodles down into the sauce (don't let any peek out - you want them to cook) and let simmer for about 15 minutes or until pasta is cooked to your desired level.
Stir in 2 Tablespoons of Greek yogurt and 1/2 cup of the shredded cheese.
Sprinkle in the remaining cheese, turn off the heat, cover and let it melt.