Cube chicken breasts into about one inch pieces (nugget sized).
In a large bowl, whisk together 3 eggs, 1 teaspoon Italian seasoning, 1 teaspoon oregano, 1/2 teaspoon salt and freshly ground pepper. Add chicken pieces to egg mixture and set aside.
In another bowl, combine 1 teaspoon Italian seasoning, 1 teaspoon oregano, 1/2 teaspoon salt, freshly ground pepper and Panko.
Remove a few chicken pieces at a time from the egg mixture (allowing excess to drain off) and toss with Panko to coat. Repeat with remaining chicken pieces.
Heat a few tablespoons of oil in a large saute pan over medium heat. (Coat the bottom of the pan.)
In about three batches, brown the chicken pieces on both sides. They do not have to be cooked through, just browned. Make sure you do it in batches (adding oil as needed) and don’t crowd the pan so they will get a nice brown crust. As they are done, place the chicken pieces in a 9 inch by 13 inch glass baking dish.
Preheat oven to 375 degrees. Wipe out saute pan and heat a bit more olive oil. Saute the sliced mushrooms.
Mix broth and Marsala together and pour over browned chicken pieces. Top with sauteed mushrooms and bake for 20 minutes. Remove from oven and place Muenster Cheese slices over top chicken and mushrooms and bake for 10 more minutes until done and bubbly. You can broil it for a bit at the end if you like the cheese browner.