Chicken Milanesa with Ranch Sauce

Name: Chicken Milanesa with Ranch Sauce
Ingredients: 1 cup mayonnaise; ½ cup crème fraîche; ¼ cup buttermilk; ½ cup finely chopped parsley; 1 tablespoon fresh lemon juice; 1½ teaspoons Maggi seasoning sauce (can swap with soy sauce); ½ teaspoon garlic powder; ½ teaspoon onion powder; ½ teaspoon freshly ground black pepper, plus more; Kosher salt; ¾ cup all-purpose flour; 3 large eggs, room temperature; 1½ cups panko (Japanese breadcrumbs); 4 small skinless, boneless chicken breasts, pounded ¼ inch thick; ½ cup vegetable oil; ½ English hothouse cucumber, thinly sliced lengthwise; 4 red radishes, trimmed, sliced; 1 tablespoon distilled white vinegar; Pinch of sugar; Aleppo-style pepper (for serving)