Chicken with Mushroom Gravy

Based on the recipe found here.

CHICKEN WITH MUSHROOM GRAVY

4 boneless, skinless chicken breasts, pounded thin
2 Tbsp. olive oil
3 Tbsp. butter
4 oz mushrooms, sliced
1 clove minced garlic
1/4 c. flour
2 c. beef broth

Heat olioil and melt 1 tbsp butter in a large skillet over high heat. Add chicken and cook for 3 minutes or until golden, then turn and cook the other side for 3 minutes. Transfer to plate, cover loosely with foil.

Add 1 tbsp butter to the skillet. Add mushrooms and cook for 3 minutes or until pretty golden. Add remaining 1 tbsp butter and garlic. Cook for 1 minute until mushrooms are golden. Turn heat DOWN to medium. Add flour and mix for 1 minute. Add about 1/4 of the beef broth, mixing as you go. Once incorporated, add remaining broth gradually, mixing constantly. This is key to avoid lumps in gravy. Use a whisk if needed (works fine even with mushrooms in there). Cook gravy for about 2 minutes or until it thickens to your taste - remember it will thicken more as it cools when serving. Adjust salt and pepper. Return chicken to the pan and turn to coat in gravy.