Heat 3 tablespoons of butter in a large sauté pan. Once melted and foaming, add the cubed chicken in a single layer, and let sit for three minutes until chicken is browned on the bottom.
Flip and sear another minute or two, seasoning with a pinch of salt, the garlic powder and Italian seasoning. Remove the chicken from the pan and set aside.
Bring a small saucepan to a medium heat; add the chicken stock and let it lightly simmer while you start the risotto.
Back in the sauté pan, add the diced onion with a small pinch of salt. Sauté the onion for a few minutes, until you start to get a little color. Add the barley and and toss it in the buttery onions to coat and toast a minute. Then, add the warm chicken stock 1/2 cup at a time, stirring the barley to absorb the liquid. Once the barley absorbs the stock, add another ladle. Keep adding stock over the course of about 20 minutes, until the barley is creamy, plump and tender.
Add the sun-dried tomatoes and the spinach, until the spinach fully wilts and pops in color. Add the chicken back to the pan.
Turn the heat off and add the last tablespoon of butter, along with the grated parmesan. Toss, and add seasoning to taste. Garnish with fresh parsley and more cheese!