Slice each breast horizontally so that you end up with 4 chicken cutlets.
Pound chicken until it is very thin. Season chicken on both sides with garlic powder, salt and pepper.
Preheat oven to 350.
Heat a non-stick pan until hot and add the olive oil. Lightly dredge the chicken in the flour, shaking off any excess. Add the chicken to the pan, cook for 4 minutes, flip and cook for 2 minutes, then put the chicken on a cookie sheet and finish in the oven, 3-4 more minutes. Cover chicken loosely with foil while you finish the sauce.
To the pan, add the shallots, season with salt and pepper, stir and cook for 2 minutes.
Add the wine and cook for 2 minutes.
Add the broth and reduce by half, 5-7 minutes.
Add the sour cream & Dijon, mix well, taste for seasoning.
Serve the chicken with the mustard sauce.
Recipe by Cook Eat Run at https://cookeatrun.com/2014/01/03/chicken-mustard-sauce/