Take your fish out 15 minutes before cooking. Pat the fish fillets dry with paper towels, then sprinkle both sides of each fillet with the salt and black pepper.
Put flour in a shallow dish. Whisk together milk and egg and place in a second shallow dish. Combine instant potatoes and Old Bay seasoning in a third shallow dish.
Dredge fish fillets in the flour, then egg/milk, and then instant potatoes.
Melt butter and olive oil in a large nonstick skillet over medium-high heat. Add fish and cook for 2 to 3 minutes on each side until golden brown and internal temp is the recommended 145 degrees F. If the outside of the fish is nice and golden brown, but the internal temp isn't quite to 145 degrees F, place the fish on a rimmed baking sheet and in the oven at 350 degrees F for about 3 minutes until done. Don't overcook the fish or it will dry out!
Like most Lent dinner ideas, it's important to keep the dish simple. The girls love eating this potato crusted fish with some roasted asparagus. But you can choose to pair it with your favorite vegetable side dish.