In a large skillet over medium-high heat, heat oil. Season chicken all over with oregano, salt, and pepper. Add chicken to skillet and cook until golden and almost cooked through in the middle, 6 minutes per side. Transfer chicken to a plate.
Immediately pour in white wine and scrape up the bottom of the skillet with a wooden spoon. (There's a ton of flavor in those stuck chicken bits!) Add butter and stir until melted, then stir in garlic and lemon juice.
Return chicken to skillet and top each breast with mozzarella. Cover and cook until cheese is melty, about 1 minute. Top with pesto and tomatoes and sprinkle with Parmesan, if using.
Recipe by 5* trending recipes with videos at https://food.theffeed.com/2021/06/21/chicken-margherita/