Here is a recipe verbatim from my 1981 edition of the famous black & red
Better Homes and Gardens Cookbook. I have never made it personally, but
it has a cornstarch glaze like you mentioned. I hope it's the one
your friend is missing.
RUSSIAN BLACK BREAD
3 1/2 to 4 c all-purpose flour
4 c rye flour
2 c whole bran cereal
2 pkgs active dry yeast
2 tablespoons instant coffee crystals
2 tablespoons caraway seed
1 tablespoon sugar
1 teaspoon fennel seed, crushed
2 1/2 c water
1/3 c molasses
1/4 c butter or margarine
1 square (1 oz) unsweetened chocolate
2 tablespoons vinegar
1/2 c cold water
1 tablespoon cornstarch
In a large mixing bowl combine 3 c of the all-purpose flour, 1 c of the
rye flour, bran cereal, yeast, instant coffee, caraway, sugar, fennel
seed, and 1 Tablespoon salt. In a saucepan, heat together 2 1/2 c water,
molasses, butter, chocolate and vinegar just until warm (115-120 F) and
chocolate and butter are almost melted; stir constantly. Add molasses
mixture to flour mixture in bowl. Beat a low speed 1/2 minute, scraping
bowl. Beat 3 minutes at high speed. Stir in remaining 3 c rye flour and
as much of the remaining all-purpose flour as you can mix in with a spoon.
Turn out into a lightly floured surface. Knead in enough remaining
all-purpose flour to make a moderately stiff dough that is smooth and
elastic (6-8 min total). Dough may be slightly stickly because of the rye
flour. Shape into a ball. Place in a greased bowl; turn once. Cover; let
rise in a warm place till nearly double (1 1/4 to 1 1/2 hours).
Punch down; divide in half. Shape each half into a ball. Place on greased
baking sheets. Flatten slightly with palm of hand to a 6 to 7" diameter.
Cover; let rise till nearly double (30-45 min). Bake at 375 for 50-60 min
or till well browned and bread sounds hollow when tapped. Remove from
baking sheets; cool.
Meanwhile, in a small saucepan combine 1/2 c cold water and cornstarch.
Cook and stir till thickened and bubbly; cook 1 min more. Brush over hot
Per serving: 126 cal; 2 g fat (recipe indicates this makes 32 servings)