Böreks are similar to spanakopita, and spinach is an oft-used filling, as are other vegetables (particularly eggplant), cheeses, and meats.
This recipe from novelist Ellen Douglas, a.k.a. Josephine Ayers Haxton makes just dozens, depending on the size, and is easily frozen before or after cooking.
Take a half pound each grated mozzarella and feta cheese, mix well with a pint of cottage cheese, two large well-beaten eggs, and a tablespoon or so of chopped parsley.
Brush phyllo with melted butter. Cut into strips an inch or so wide, and three or four inches long. Place a spoonful of the cheese filling at the top edge of the strip and fold “like you fold a flag” into triangles or flip into squares.
Pinch the edges and brush with an egg white beaten in a half cup of water. Sprinkle with sesame or poppy seeds and bake twenty minutes or so at 375.