Pour milk over kidneys in non-reactive bowl. Add enough water to cover kidneys.
Cover and refrigerate for 1 hour.
Drain and rinse kidneys; pat dry. Cut kidneys lengthwise
into halves. Remove fat and membranes with kitchen scissors. Cut kidneys into 1-inch
Heat oil in 12-inch skillet until hot. Cook and stir kidneys in oil over medium
heat until brown on all sides, about 8 minutes; remove with slotted spoon.
Cook and stir onion and garlic in remaining oil until onion is tender.
Remove from heat; stir in flour.
Gradually stir both into flour mixture.
Stir in sherry, salt, pepper and kidneys. Heat to boiling, stirring constantly; reduce
heat. Simmer uncovered, stirring occasionally, until kidneys are no longer pink
inside and sauce is thickened, about 10 minutes.