Crisp on the outside, creamy on the inside, these make tasty hors d'oeuvres.
Place bread in the bowl of a food processor. Process until crumbs form, about 10 seconds. Transfer crumbs to a medium bowl; set aside. Line one baking sheet with parchment, and another one with a double thickness of paper towels; set both aside.
In a small bowl, combine potatoes, herbs, egg, and flour using a fork or spoon. Season with salt and pepper. Using a spoon, scoop mixture into an egg-shaped piece. Using a second spoon, push shape into the bowl of bread crumbs. Roll to coat, and transfer to parchment-lined baking sheet. Repeat with remaining potato mixture.
Place oil in a small deep saucepan. Heat over medium heat until a frying thermometer registers 350 degrees. Using slotted spoon, place five croquettes in oil. Cook until golden and puffed, turning once, 4 to 5 minutes. Using slotted spoon, transfer to paper-towel-lined baking sheet. Repeat with remaining croquettes. Serve immediately.
The batter should taste a little salty, but once you fry the croquettes, the seasoning will be perfect.