Prepare everything necessary. Take out the puff pastry in advance to thaw. Frozen spinach is used here.
Chop the onion into cubes, fry in oil until transparent and slightly golden. Add the spinach cut into strips, do not defrost the frozen one.
50 g spinach, 100 g onion, 30 ml vegetable oil
Hold until the greens wilt. This happens literally in a minute. Transfer to a plate. Let cool.
Crumble the feta with your hands, add chopped garlic, herbes de Provence, and a little salt if necessary. Mix.
200 g cheese, 2 cloves garlic, ¼ tsp herbes de Provence, 1 pinch salt
Whisk the egg, leave a third for greasing, pour the rest into the filling.
1 pc egg
Roll out the dough a little, about 3 mm thick. Distribute the prepared mixture of cheese, spinach, and onion, leaving a couple of centimeters free on all sides.
400 g puff pastry
Make one turn, tuck the side edges.
Continue rolling. Lay seam down. Grease with the egg left earlier.
Make incisions. This will prevent the strudel from cracking, which often happens during baking. Sprinkle with sesame seeds.
1 tsp sesame seeds
Bake in the oven for 30 minutes, temperature 170 ℃. The strudel with Feta cheese and spinach can be served immediately, but it is much tastier and more aromatic after cooling.