In a shallow bowl or large plate, stir flour, salt, and lemon pepper together.
Dredge each piece of chicken with flour mixture, making sure to cover all sides.
Heat olive oil with 2 Tbsp butter in a large nonstick skillet over medium-heat. Add the chicken pieces and cook until golden brown, about 5 minutes per side. Remove from pan.
Add mushrooms, oregano, and garlic to pan and saute until mushrooms are softened.
Stir in chicken broth and lemon juice. Bring to a boil, scraping up brown bits from bottom of pan.
Stir in remaining Tbsp butter and cook for 2 minutes. Add parsley and remove from heat. Spoon sauce and mushrooms over chicken and serve.
Recipe by Simple, Sweet & Savory at https://www.simplesweetsavory.com/lemon-mushroom-chicken/