Cut each chicken breast horizontally into 2 cutlets. Use a meat mallet to pound any thick parts to even thickness for uniform cooking.

Mix garlic powder, mixed herbs, salt, and pepper in a small bowl. Season both sides of each chicken cutlet generously.

Heat olive oil and 1.5 tablespoons butter in a cast-iron skillet over medium-high heat. Once sizzling, sear chicken cutlets for 3-4 minutes per side until golden brown. Remove to a plate and cover loosely with foil.

In the same skillet, melt 1 tablespoon butter over medium heat. Add minced garlic and saute for 30 seconds until fragrant.

Sprinkle flour into the garlic butter and cook for 30 seconds, stirring constantly to create a roux.

Slowly add chicken stock while whisking constantly to prevent lumps and create a smooth sauce.

Lower heat and whisk in sour cream and ranch seasoning until sauce becomes glossy and thick. Turn off heat.

Return chicken to the skillet, spoon sauce over the top, and garnish with fresh chopped parsley. Serve immediately.