Preheat the oven to 400°F (200°C). Line a baking dish with parchment paper or lightly grease it.
Pat chicken breasts dry with a paper towel.
Rub chicken with olive oil, salt, and pepper.
Place chicken in the prepared dish.
Bake for 20–25 minutes, or until internal temperature reaches 165°F (74°C).
While the chicken bakes, combine mayonnaise, Dijon mustard, Parmesan, lemon juice, and garlic in a small bowl.
Season with salt and pepper to taste.
Mix until smooth.
