Crispy Fish Fillets

1 egg
2 tablespoons prepared yellow mustard
1/2 teaspoon salt
1 1/2 cups instant mashed potato flakes
1/4 cup oil for frying
4 (6 ounce) fillets sole

In a shallow dish, whisk together the egg, mustard, and salt; set aside.
Place the potato flakes in another shallow dish.
Heat oil in a large heavy skillet over medium-high heat.
Dip fish fillets in the egg mixture.
Dredge the fillets in the potato flakes, making sure to completely coat the fish.
For extra crispy, dip into egg and potato flakes again.
Fry fish fillets in oil for 3 to 4 minutes on each side, or until golden brown.