Season the chicken with salt & pepper.
In a bowl, combine the flour, parmesan cheese and garlic powder. Cover the chicken in the flour mixture.
Heat oil and butter in a large pan over a medium-high heat. Swirl pan to coat evenly.
Fry chicken breasts until golden on each side, cooked through and no longer pink (about 4-5 minutes each side, depending on the thickness of your chicken). Transfer to a warm plate and set aside. Repeat with remaining oil, butter and chicken breasts. When cooked, transfer the chicken onto the same plate.
Reduce heat to medium/low. Sauté the onion in the remaining oil/juices in the pan until softened.
Add the garlic to the pan; half of the cloves should be added whole, the other half crushed/finely diced. Sauté the smashed garlic cloves and whole garlic cloves until fragrant, about 2-3 minutes.
Add the chicken stock to deglaze the pan. Scrape up any browned bits and let simmer and reduce to half, about 5 minutes.
Pour in the cream. Bring the sauce to a gentle simmer for about 2-3 minutes, combining all of the flavours together.
Mix in the parmesan cheese. Continue cooking gently for about 2-3 minutes until cheese melts, while stirring occasionally. Season with salt and pepper to your taste and add the parsley.
Add the chicken back into the pan and let simmer for a further 2-3 minutes to thicken the sauce to your liking and to ensure the chicken is hot.
Serve and enjoy!