Spinach, fennel frond, and feta pies with a Greek yogurt filo pastry

Spinach, fennel frond, and feta pies with a Greek yogurt filo pastry. Called kourou, this pastry is so simple to make and I love that it uses yogurt. Watch out for the recipe shown step by step in my stories!

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#RECIPE
1 cup (225g) butter, softened
1 cup (200g) Greek yogurt
3 cups (375g) self rising flour
1/2 tsp salt
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Beat butter till light and creamy, about 5 min. Add yogurt and beat another minute. Add flour and salt and knead till a soft dough forms (I used the dough hook of my stand mixer). Cover and rest for 30 min.
For the filling: sauté 4 green onions in 3 tbsp olive oil till soft. Add 300g frozen spinach, the chopped fronds of one fennel bulb (about 2/3-1 cup total), 3 tbsp chopped fresh dill, salt and pepper. Cook till liquid has evaporated and mixture is dry. Remove from heat, cool slightly, then add about 5 oz (150g) crumbled feta and 1 egg.
Roll pastry out in batches on a lightly floured surface. Cut out circles about 3 inches (7cm) in diameter. Fill each with 1 tsp filling. Seal edges with beaten egg. Place pies on a parchment lined baking sheet, then brush tops with beaten egg and sprinkle with sesame seeds.
Bake at 400F (200C) for 10-15 min, or till golden.