Mix ½ cup flour with ¼ cup bread crumbs, 1 tbsp garlic powder, 1 tbsp onion powder, 1 tbsp parsley flakes, 1 tsp of pepper and a pinch of salt. Crack 1 egg in separate bowl and beat. Prepare chicken pieces by dipping in flour mixture, then covering in egg and then dredging in flour mixture again. Set aside.
In a semi-deep, coverable frying pan, sauté onion and garlic with enough olive oil to coat. Add salt and pepper to taste. Sauté for 1 minute. Add enough Marsala wine to cover bottom of pan. Brown chicken on either side for 30 seconds to one minute until flour mixture is cooked through and adheres to chicken. Take out and set aside.
In same pan, add more Marsala wine to deglaze the pan. Add beef broth, ¼ cup Marsala wine, butter, Dijon mustard, 1 tbsp of garlic powder, 1 tbsp of Onion Powder, 1 tbsp Parsley Flakes, ½ tsp of pepper, pinch of salt (remember most beef broth has a lot of salt, so be gentle). Bring to a boil, then simmer. Add chicken (only when it has stopped boiling, no sooner) Cover and simmer for 30 mins.
Take chicken out and set aside. Using the broth/Marsala mixture slowly stir in 2 tbsp of flour to thicken sauce. Stir until fairly smooth, try to get all lumps out. Simmer for approximately 10-15 minutes more to allow tho thicken. Finish of with a little fresh parsley or parsley flakes about a minute before serving. You can put chicken back in sauce about 2 minutes before serving to warm it.