In a large glass bowl, mix all the marinade ingredients.  Add the sliced chicken and enough water to cover.  Place in the fridge overnight or at least 8 hours.

When you're ready to cook, mix the flour ingredients together in a medium bowl.

Heat olive oil and 2 tbsp. butter in a large frying pan over medium heat.

Dip chicken into the flour mix, then place into a pan to fry (probably in 2 batches).  Add the garlic along with the chicken.

Set chicken aside when cooked through.

In the pan, add the remaining butter, onion, and mushrooms.  Cook until mushrooms are done (softened).

Add marsala wine and deglaze the pan (stir around to get all the browned bits off the bottom).

Add chicken broth and a bit of salt and pepper.

Boil for 15 – 20 minutes until reduced by half.

At this point, either add the chicken back to the pan to coat it with sauce or pour it over the chicken on serving plates.