01 - In a large mixing bowl, combine bread flour, yeast, salt, and sugar. Mix thoroughly to distribute yeast and salt evenly throughout the flour.
02 - Pour warm water and olive oil into the flour mixture. Stir with a wooden spoon until a shaggy, sticky dough begins to form and all dry ingredients are incorporated.
03 - Knead by hand on a lightly floured surface or with a stand mixer fitted with a dough hook for 5–7 minutes. Continue until dough becomes smooth, elastic, and pulls away from the sides of the bowl.
04 - Gently fold chopped spinach and drained cottage cheese into the dough. Knead briefly until evenly distributed. The dough will remain slightly sticky due to the cheese moisture.
05 - Transfer dough to a lightly oiled bowl, turning once to coat all surfaces. Cover with plastic wrap or a damp towel. Place in a warm, draft-free area for 1 hour, or until dough has doubled in size.
06 - Preheat oven to 425°F. Line a large baking sheet with parchment paper and set aside.
07 - Turn risen dough onto a lightly floured surface. Divide into 8 equal portions using a bench scraper or sharp knife.
08 - Shape each portion into a smooth ball. Flatten each ball to approximately 1/2 inch thickness. Press your thumb through the center and gently stretch to form a 4-inch ring, maintaining the flattened characteristic of flagels.
09 - Arrange shaped flagels on the prepared baking sheet, leaving 2 inches between each. Cover loosely with a clean towel and let rest for 15 minutes.
10 - Brush the tops of each flagel generously with beaten egg using a pastry brush. Sprinkle sesame seeds or poppy seeds over the surface if desired.
11 - Bake for 18–20 minutes, rotating the baking sheet halfway through. Flagels are done when deep golden brown and sound hollow when tapped on the bottom.
12 - Transfer flagels to a wire rack and cool for at least 15 minutes before slicing. Serve warm or at room temperature, toasted with butter or as sandwich bases.