Heat a large skillet on medium high heat and add oil to your pan.
Sprinkle salt and pepper evenly on all chicken breasts. Spread 1 tsp of mustard on each chicken breast.
Next mix your hashbrowns with the garlic salt.
Top each breast mustard side up with hashbrowns and press down to make sure the hashbrowns stay on the chicken breasts.
Add each chicken breast hashbrown side down to your hot pan. Cook for 5 minutes without touching the chicken. As soon as you see the sides of the hashbrowns turning a golden color carefully flip the chicken breasts over. Continue to cook for an additional 3 minutes.
Turn your heat down to low, cover and cook the chicken for 10 minutes or until the chicken is fully cooked and no longer pink.