Ingredients

• 2 lbs boneless, skinless chicken breast (about 3–4 chicken breasts)
• 1/2 tsp garlic powder
• 1/2 tsp salt
• 1/2 tsp pepper
• 1/2 cup mayonnaise
• 1/2 cup sour cream
• 2 tsp Dijon mustard
• 1/4 onion, finely chopped
• 8 oz mozzarella cheese, grated
• 3 oz freshly grated Parmesan cheese
• 1/2 can artichoke hearts, drained and diced
• 4 cups fresh spinach, coarsely chopped (about 2 oz)

Instructions

1. Preheat the oven to 375°F. Arrange the chicken breasts in a large baking dish in a single layer. Season them evenly with garlic powder, 1/4 teaspoon salt, and 1/4 teaspoon pepper.
2. Combine the mozzarella and Parmesan cheeses in a bowl. Remove about one-third of the cheese mixture (roughly 1 cup) and set it aside.
3. In a separate large bowl, stir together the mayonnaise, sour cream, Dijon mustard, chopped onion, remaining salt, and remaining pepper. Mix in the remaining cheese, then gently fold in the chopped spinach and diced artichoke hearts.
4. Spoon the creamy mixture evenly over the chicken breasts. Sprinkle the reserved cup of cheese over the top.
5. Place the dish on the middle rack of the oven and bake for 30–40 minutes, or until the chicken is fully cooked and reaches an internal temperature of 165°F.
6. Serve immediately while hot.

• Leftovers can be kept in an airtight container in the refrigerator for up to 3 days, or frozen for up to 3 months for later use.