Step 1: In a shallow bowl, whisk together the grated parmesan cheese, flour, dried oregano, salt, and black pepper to create the coating for the lemon garlic parmesan chicken.
Step 2: Pat the chicken breasts dry with paper towels and dredge each piece in the flour mixture, pressing firmly so the coating adheres to both sides.
Step 3: Heat olive oil and 1 tablespoon of butter in a large skillet over medium-high heat. Once the butter is foaming, add the chicken to the pan.
Step 4: Cook the chicken for 5-6 minutes per side until golden brown and the internal temperature reaches 165°F (74°C). Remove the chicken from the pan and set aside on a plate.
Step 5: In the same skillet, add the remaining 2 tablespoons of butter and the minced garlic. Sauté for 1 minute until fragrant, then pour in the chicken broth and lemon juice to complete the lemon garlic parmesan chicken sauce.
Step 6: Simmer the sauce for 2-3 minutes, scraping up the browned bits. Return the chicken to the pan, spoon the sauce over it, and garnish with lemon slices and fresh parsley before serving.