Preheat oven to 200°. Combine yeast and 1 cup warm water in a 1-cup liquid measuring cup; let mixture stand 5 minutes.
Combine flour, sugar, and salt in a heavy-duty mixing bowl. Add yeast mixture and oil. Beat at low speed with an electric mixer 1 minute; beat at medium speed 5 minutes.
Divide dough into 20 equal portions. Shape each portion into a 7-inch rope, and shape into a knot. Combine egg yolk and 1 tablespoon water; brush over rolls. Sprinkle with seeds; place on parchment paper-lined baking sheets. Turn oven off, cover rolls loosely with plastic wrap; place in oven, and let rise 15 to 20 minutes or until doubled in bulk. Remove from oven, and preheat oven to 400°. Discard plastic wrap.
Bake at 400° for 15 to 17 minutes or until golden.