Spanakopita with Homemade Phyllo

Steps

1. Chop the spinach, place in a bowl, sprinkle with coarse sea salt, and let sit to release excess liquid; drain and squeeze dry.
2. Make the phyllo dough: combine 450 g flour, ⅔ tbsp salt, 1 tbsp olive oil, red wine vinegar, and water in a bowl; knead into a smooth, elastic dough.
3. Divide the dough into equal balls, cover, and let rest to relax the gluten.
4. Prepare the filling: mix the drained spinach, chopped red onion, spring onions, leek, dill or fennel greens, spearmint, 2 tbsp olive oil, pepper, and crumbled feta (if using) in a large bowl.
5. Prepare a paste by mixing 80 g flour, 80 g cornstarch, and 180 ml olive oil; this will be brushed between dough layers to keep them separate while rolling.
6. Roll each dough ball out thinly, brushing the cornstarch-oil paste between stacked layers, then roll all layers together into one large thin sheet of phyllo.
7. Layer the phyllo sheets in a baking pan, spreading the spinach and feta filling evenly between them.
8. Fold or roll the assembled spanakopita as desired, brushing the top with olive oil.
9. Bake until golden brown and crisp, then let cool slightly before slicing into pieces to serve.