Cut the chicken breasts into 1-inch cubes.
Heat a large heavy-based skillet with a lid over medium-high heat. Melt the butter in the skillet, then add the chicken cubes and brown on all sides for 2-3 minutes.
Add the garlic and sauté for a few minutes, then pour in the pasta, the chicken stock, and the whole milk, and stir. Put the lid on the skillet and bring the liquid to a boil, then turn it down and let it simmer for 10 minutes.
dd the basil pesto, cream cheese, Parmesan, sundried tomatoes, and spinach. Stir it together and let it simmer for another 10 minutes. Make sure it doesn’t stick to the bottom by keeping the stove on low heat and stirring occasionally.