Mix flour, eggs, milk, melted butter, a pinch of salt, and and pinch of pepper into a ball of dough; let sit at room temperature for 10 minutes.

Cut dough ball into quarters. Roll each piece into logs. Press each log flat.

Bring a large pot of water to a boil; add potatoes. Hold a flattened dough log over the water and use kitchen shears to diagonally snip 1/4- to 1/2-inch pieces of dough into the water; repeat until all dough is in the water. Cook potatoes and dough, stirring occasionally, until the potatoes are tender and the dough is cooked into small dumplings, 15 to 20 minutes; drain and transfer potatoes and dumplings into a large bowl.

Crush the toasted bread into the noodles and mix with a spoon.