Place chicken cutlets on cutting board. Liberally season all sides of each cutlet with salt, pepper, and garlic powder. Set chicken aside.
Place 6 cloves garlic on clean cutting board or other flat surface. Carefully use side of large knife to smash garlic cloves. Leave remaining 4 to 6 cloves whole. Set garlic aside.
Heat large skillet over medium heat. When skillet is hot, add neutral oil and swirl pan to distribute oil evenly across entire bottom surface of skillet. Heat oil over medium heat until oil is hot and shimmery.
When oil is hot, place seasoned chicken cutlets in skillet. Fry cutlets until golden, approximately 4 to 5 minutes, then carefully flip cutlets over and fry another 4 to 5 minutes or until cutlets are golden brown and cooked through. Transfer cooked cutlets to plate and set aside.
When cutlets have been transferred to plate, add 2 tablespoons butter to skillet. Melt butter completely, swirling pan occasionally to distribute butter.
Add chopped onion to melted butter. Sauté onions until softened and translucent, approximately 10 minutes.
Once onion is softened, add smashed and whole garlic cloves to skillet. Sauté until garlic is fragrant, approximately 2 to 3 minutes.
When garlic is fragrant, pour white wine into skillet to deglaze pan. Use spatula or tongs to scrape up any browned bits of chicken or onions that may be stuck to skillet.
When skillet is deglazed, pour in 1 cup chicken broth. Stir to incorporate. Raise heat to medium-high and bring liquid to boil. When liquid begins to boil, reduce heat to medium-low and simmer until liquid has reduced by 50%, approximately 5 minutes.
Once liquid has reduced, remove skillet from heat. Add 1 ½ cups half and half and ½ cup grated parmesan to skillet. Stir to incorporate, and continue stirring until parmesan has melted.
Return skillet to heat and let sauce simmer 3 minutes, or until mixture has thickened slightly. Season sauce with salt and black pepper to taste.
Return chicken cutlets to skillet. Spoon sauce over tops of cutlets and let chicken rest in skillet until warmed through. When ready, transfer chicken to serving plates. Serve warm with mashed potatoes or mashed cauliflower. When serving, garnish cutlets with plenty of creamy garlic sauce, additional grated parmesan, and chopped parsley.