1/2 cup butter
1/2 cup all-purpose flour
1/2 teaspoon salt
1/2 teaspoon dried oregano
1 (4 ounce) can sliced fresh mushrooms, drained
1 large onion, diced
1/2 teaspoon Worcestershire sauce
2 teaspoons Worcestershire sauce
2 tablespoons black pepper
3 tablespoons lemon juice
1 (1 ounce) square unsalted butter, melted
3 tablespoons olive oil
1 pound shredded Cheddar cheese
2 tablespoons grated Parmesan cheese
1 pound fresh mushrooms, sliced
1 cup diced celery
Melt butter in a medium skillet over medium heat. Stir in 1/2 cup flour, salt, oregano, mushrooms, onion, and Worcestershire sauce. Bring to a boil, then add pepper and lemon juice. Stirring constantly, cook for about 10 minutes, or until thickened.
Reduce heat to medium-low and add butter, olive oil, cheese, mushrooms, celery, onion, Worcestershire sauce, Worcestershire sauce, black pepper, lemon juice. Bring to a simmer, reduce heat, and simmer for 10 minutes.
Stir in bread crumbs, Cheddar cheese, Parmesan cheese, mushrooms, celery and celery. Sprinkle with Cheddar cheese mixture. Place chicken in bottom of 9x13 inch baking dish. Fill with tomato sauce.
Bake uncovered at 350 degrees F (175 degrees C) for 35 minutes. Turn chicken breasts over and brush with egg. Baste with tomato sauce. Reduce heat to low and bake for 10 minutes.
Remove chicken from baking dish. Brush with tomato sauce. Cover dish and bake uncovered for 25 minutes. Preheat oven to 375 degrees F (190 degrees C).