Slice the chicken breasts into thin cutlets, ensuring even cooking. In a mixing bowl, whisk together the egg and milk, then add garlic powder, salt, and pepper. Dip each chicken cutlet into the egg mixture, allowing any excess to drip off, before coating it evenly in breadcrumbs.

Heat oil in a shallow pan over medium-high heat to 350°F. Carefully place the breaded chicken cutlets in the hot oil and fry for about 5 minutes on each side until golden brown and crispy. Transfer to paper towels to drain excess oil.

In a small bowl, mix softened butter, mayo, minced garlic, and chopped parsley. Slice the hoagies or baguette in half and spread the garlic butter mixture on the inside. Toast the bread in a preheated oven at 450°F for 3-4 minutes.

In another mixing bowl, combine mayo, sour cream, Parmesan, lemon juice, Dijon mustard, anchovy paste, Worcestershire sauce, minced garlic, and a pinch of salt and pepper. Whisk until smooth and creamy.

Layer the crispy chicken cutlets on one side of the toasted bread. Top with dressed romaine lettuce and an extra sprinkle of Parmesan cheese. Place the other half of the toasted bread on top.

Cut the assembled sandwiches in half and serve while warm and crunchy.