Start by seasoning the chicken breasts evenly with salt, pepper, and garlic powder. I like to gently press the seasoning into the meat so it sticks better. Letting the chicken sit for a few minutes helps the flavor sink in before cooking.
Heat olive oil in a large skillet over medium-high heat. Place the chicken in the pan and cook until golden brown on both sides. The goal is to develop a crust, not fully cook it through yet.
Transfer the chicken to a plate once browned. This resting step keeps the chicken juicy and prevents overcooking while the sauce is prepared. Don’t wipe the pan; those browned bits are flavor gold.
Lower the heat slightly and add butter to the same skillet. Once melted, stir in minced garlic and cook briefly until fragrant. Be careful not to let the garlic burn, as it can turn bitter.
Pour in the chicken broth and gently scrape the bottom of the pan. This lifts all the savory bits left behind from the chicken. Let it simmer for a few minutes to reduce slightly.
Stir in the heavy cream and let it gently simmer. Add the freshly grated parmesan slowly, stirring constantly until the sauce thickens. The sauce should coat the back of a spoon.
Return the chicken to the skillet and spoon the sauce over it. Sprinkle in chopped fresh basil and red pepper flakes if using. Let everything simmer together until the chicken is cooked through.
Taste the sauce and adjust seasoning if needed. I usually add a little extra parmesan at this stage. Serve hot, with plenty of sauce spooned over the chicken.