Onion-Rye Flatbreads

Instructions

1. Cook onion in oil with 1/4 teaspoon salt in an 8- to 9-inch nonstick skillet over moderately low heat, stirring, until softened, about 6 minutes, then cool.
2. Stir together yeast, honey, and 1/4 cup milk in a small bowl and let stand until foamy, about 5 minutes.
3. (If mixture doesn't foam, discard and start over with new yeast.)
4. Stir together flours, pepper, and remaining 1 1/4 teaspoons salt in a large bowl, then add yeast mixture, onion mixture, and remaining 3/4 cup milk, stirring until a soft dough forms.
5. Turn out dough onto a floured surface and knead, adding just enough additional flour to prevent sticking, until smooth and elastic, about 8 minutes.
6. Form dough into a ball and transfer to an oiled large bowl, turning to coat.
7. Cover bowl with a clean kitchen towel and let dough rise in a draft-free place at warm room temperature until doubled in bulk, at least 1 hour (see cooks' note, below).
8. Oil 2 large baking sheets and sprinkle with cornmeal, shaking off excess.
9. Turn out dough onto a lightly floured surface and knead several times to remove air.
10. Divide dough in half and roll out 1 half with a floured rolling pin into a 12-inch round (1/2 inch thick).
11. Transfer round to one of baking sheets and prick all over at 1-inch intervals with a fork, then cover loosely with oiled plastic wrap (oiled side down).
12. Make another round in same manner and transfer to other baking sheet.
13. Let rounds rise slightly in a draft-free place at warm room temperature 30 minutes.
14. While rounds rise, put oven racks in upper and lower thirds of oven and preheat oven to 400F.
15. Gently brush rounds with some egg wash, being careful not to deflate dough, then sprinkle with caraway seeds.
16. Bake, switching position of sheets halfway through baking, until tops are golden and bottoms sound hollow when tapped, 12 to 16 minutes total.
17. Transfer flatbreads to a rack to cool slightly.
18. Serve warm or at room temperature.