Bring a large pot of water to a boil and cook penne pasta according to package directions. Once cooked, reserve ½ cup of pasta water, drain, and set aside.
Cook the chicken:
Butterfly the chicken breasts and cut them into four pieces. Pat them dry with a paper towel and season on both sides with salt and pepper.
Heat a skillet over medium-high heat. Once hot, add the oil and 1 tablespoon of butter. Once the butter is melted, place the chicken pieces on the pan and cook for 4 to 5 minutes on the first side without disturbing them, flip, and cook for 3 to 4 additional minutes on the other side, until the internal temperature reaches 165F. Remove the chicken from the pan onto a board and set aside.
Make the sauce:
Reduce heat to medium and add the remaining tablespoon of butter onto the pan. Add the whole garlic cloves and sauté them for about 2 to 3 minutes, moving them around to make sure they toast to a golden color, but they don’t burn.
Add the rosemary to the pan and toast it for about 30 seconds. Add the chicken broth or stock, and as it simmers, use a wooden spatula to scrape the tidbits from the bottom of the pan. Add warmed cream to the pan and stir, bringing it to a simmer, and then cook it down for about 4 minutes. While the sauce is simmering, slice the cooked chicken breasts diagonally.
Make it a meal:
Add the sliced chicken to the sauce, reduce the heat to low, and simmer it in the sauce for 5 minutes. Add the cooked pasta to the pan and toss to combine. Slowly, add ¼ cup of the reserved pasta water, to the pan and toss to combine. If needed, to thin out the sauce, add a bit more of the pasta water.
Serve:
Serve the creamy garlic chicken pasta sprinkled with parmesan cheese.
Notes
Use ¼ teaspoon dried rosemary or poultry seasoning instead of fresh rosemary