Step 1

Arrange a rack in the middle of the oven and heat the oven to 400ºF.

Step 2

Drain and coarsely chop 1 can or jar artichoke hearts. Cube 4 ounces cream cheese and place in a large microwave-safe bowl. Microwave on HIGH until very soft, about 30 seconds. Add the chopped artichoke hearts, 8 ounces sour cream, 2 cups baby spinach, 1/2 cup of the shredded Italian cheese, 1 teaspoon Dijon mustard, and 1/2 teaspoon garlic powder, and stir to combine.

Step 3

Pound 4 boneless, skinless chicken breasts one at a time: Place 1 chicken breast in a gallon-sized zip-top bag and pound with a rolling pin or the flat side of a meat mallet to an even 1/2-inch thickness.

Step 4

Place the chicken breasts in a baking dish large enough to fit them in a single layer and season all over with 1 teaspoon kosher salt and 1/4 freshly ground black pepper. Spread the spinach-artichoke mixture over the chicken in an even layer.

Step 5

Bake until the chicken is cooked through and registers 165°F on an instant-read thermometer, 20 to 25 minutes.

Step 6

Remove the baking dish from the oven. Heat the oven to broil. Sprinkle the chicken with the remaining 1 cup shredded Italian cheese. Broil until the cheese is melted and lightly browned, 3 to 4 minutes.