- 4 small skinless, boneless chicken breasts, cubed
- 1 teaspoon dried parsley
- 1 teaspoon dried oregano
- 1 teaspoon dried basil
- 1/2 teaspoon salt
- 1/4 teaspoon ground black pepper
- 1 cup bread crumbs
- 1 cup grated Parmesan cheese
- 1/4 cup butter, divided
- 4 slices bread
- 1/3 cup chopped onion
- 1 clove garlic, minced
- 4 mushrooms, thinly sliced
- 2 tablespoons all-purpose flour
- 1 (8 ounce) can spaghetti sauce
- Preheat oven to 400 degrees F (200 degrees C).
- Combine chicken breasts, parsley, oregano, basil, salt, and pepper in a food processor; process into a smooth paste. Shape chicken mixture into 2 round patties.
- Mix bread crumbs and Parmesan cheese together in a shallow bowl. Dredge patties to coat both sides. Arrange on an ungreased baking sheet.
- Spread 1 1/2 teaspoon butter over each slice of bread; sprinkle remaining bread crumb-Parmesan mixture on top. Arrange near the chicken patties on the baking sheet.
- Bake in the preheated oven until bread is browned, 10 to 15 minutes. Transfer bread to a serving plate. Continue baking chicken until an instant-read thermometer inserted into the center reads 165 degrees F (74 degrees C), 10 to 15 minutes more.
- Melt remaining 2 tablespoons butter in a saucepan. Cook and stir onion and garlic in the butter until onion is translucent, about 5 minutes. Add mushrooms and flour; cook and stir until starting to brown, about 5 minutes. Stir in spaghetti sauce; simmer until thickened, 5 to 10 minutes.
- Spoon sauce over 2 bread slices. Place a chicken patty in the center; cover with remaining bread slices.