You'll want to make cracker crumbs. If you've had a bad day, just take crackers and put them in a baggie and smash them. I use a full can of soup or broth if I don't have a handy rolling pin. Croutons make good crumbs for this dish too. Take out your aggressions on the crackers. What flavor of crumbs you choose will make a slight difference in the dish, but why limit yourself to soup crackers? If you are doing low-carb, use whole wheat crackers. You choose.
Mix the cracker crumbs, cheese, parsley and salt and pepper on a large plate. Put the first half cup of melted butter on a smaller plate. You are setting up an assembly line.
One at a time, place each chicken breast in a plastic bag. Use the same soup can or a meat mallet to flatten the chicken breast to less than one-half inch in thickness. Just squish down the fattest parts so it will cook faster and spread it out. Try to keep the extra piece (the tenderloin) that sticks off still attached, but don't worry if it falls off. When one breast is squished, take it out of the bag, roll it in the butter and then put it in the crumb mixture and turn it over. You want to coat both sides. Press it down so you get crumbs and cheese mixture all over. Then do the next breast, and then do it again until you get all 4 ready to go.
Now heat the olive oil in your large saut? pan. Put in all 4 breasts. Cook on Medium High just 3 to 5 minutes until you get the first side nicely browned. Turn over. Brown the second side. When all 4 breasts are browned on both sides, you?re ready for the oven. If your sauté pan is okay to put in the oven, you can just pop them in. If the handle is not oven proof you'd better put them in another pan. A 9 by 13 oven-proof pan will do just fine. Squeeze the lemon over the chicken and pop the pan in the oven. The chicken will only take 15 to 20 minutes at 425 degrees to cook because you've already partially cooked it in the sauté pan and because you flattened it to make it cook faster.
Port Wine-Mushroom Sauce:
Heat your butter and olive oil in a medium sauté pan. Add shallots. Cook over medium heat until the shallots just begin to cook. Add mushrooms. Cook for 5 to 7 minutes until the mushrooms begin to brown. Add flour and port. Cook quickly to boil off half of the port, and then add the half and half. This sauce will thicken up fast, so turn down the heat and add the nutmeg. The only trick to this is to try to time the sauce thickening to when your chicken is about done. But don't worry. If the sauce seems too thick before your chicken is done, just turn it off. When the chicken is coming out of the oven, let it sit on the counter and add a little more half and half to your sauce, then turn the sauce back on Medium Low and reheat the sauce until it's at a consistency you like. Then serve.
After the 15 minutes of baking time, check one piece of the chicken by cutting into it at the fattest point. If you don't see any pink, you are ready to eat and you can put on the sauce.