"Plain old chicken breasts just got a major upgrade...."
skinless, boneless chicken breasts (about 2 pounds)
Kosher salt and black pepper, to taste
salted butter
olive oil
garlic cloves, minced
white wine or brandy
heaping tablespoons grainy mustard
chicken broth, or more as needed
chopped mixed herbs (such as dill, parsley, or chives), plus more for garnish
Buttered egg noodles, for serving