Preheat your oven to 375°F (190°C) to ensure even cooking.
In your baking dish, arrange the sliced or pounded chicken breast in a single layer and season lightly with salt and pepper if desired.
Spread the prepared pesto evenly over the chicken, ensuring each piece is well-coated.
In a mixing bowl, combine the fresh baby spinach, chopped roma tomatoes, and quartered artichoke hearts. Toss gently and layer over the chicken.
Sprinkle the shredded mozzarella cheese over the vegetables for a cheesy topping.
Bake in the preheated oven for 25-30 minutes, or until the chicken is cooked through and the cheese is bubbly and golden.
Remove from the oven, let cool for a few minutes, then serve warm, garnished with fresh spinach or herbs if desired.