Begin by cutting the two large chicken breasts in half lengthwise to create four thin cutlets. Season both sides generously with salt and pepper, then dredge each cutlet in flour, setting them aside.

Heat a large skillet over medium-high heat and add the olive oil. Sear the chicken cutlets for about 4-5 minutes on each side until golden brown. Remove from skillet and cover to keep warm.

In the same skillet, add the butter. Once melted, add the sliced mushrooms and Italian seasoning. Cook for 5-7 minutes until browned. Remove and set aside.

Lower heat to medium and add the minced garlic. Stir for about 30 seconds, then add chicken broth, lemon juice, and Dijon mustard, simmering for 3-4 minutes.

Pour in the heavy cream and stir well. Return chicken and mushrooms to the skillet, simmer for an additional 5 minutes until fully cooked and sauce thickens.