01 - In a large mixing bowl, combine bread flour, instant dry yeast, fine sea salt, and granulated sugar. Mix thoroughly to distribute all ingredients evenly.
02 - Pour warm water and olive oil into the dry mixture. Stir with a wooden spoon until a shaggy, rough dough forms.
03 - Knead by hand on a floured surface or with a stand mixer fitted with a dough hook for 5–7 minutes until the dough becomes smooth, elastic, and pulls away from the sides of the bowl.
04 - Gently fold the chopped spinach and drained cottage cheese into the dough. Knead for 2–3 minutes until evenly distributed. The dough will feel slightly sticky due to the cheese moisture.
05 - Transfer the 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 until doubled in volume.
06 - Preheat oven to 425°F. Line a large baking sheet with parchment paper.
07 - Turn the risen dough onto a lightly floured surface. Divide into 8 equal portions using a bench scraper or knife.
08 - Roll each portion into a smooth ball. Flatten each ball to approximately 1/2 inch thickness. Press your thumb through the center and gently stretch the opening to create a 4-inch ring, maintaining a flat, disc-like shape.
09 - Place shaped flagels on the prepared baking sheet, leaving 2 inches between each. Cover with a clean kitchen towel and let rest at room temperature for 15 minutes.
10 - Brush the tops of each flagel with beaten egg using a pastry brush. Sprinkle sesame seeds or poppy seeds evenly over the surface if desired.
11 - Bake for 18–20 minutes until the flagels develop a deep golden-brown crust and sound hollow when tapped on the bottom.
12 - Transfer flagels to a wire cooling rack. Let cool completely for at least 30 minutes before slicing or serving.