Borek is a filled baked pastry dish, similar to gozleme. Different areas of the Mediterranean have different styles of filling, which can include meat, potatoes, or soft cheese and spinach. Ours uses beef, haloumi and spinach. Depending on the region and filling, borek is eaten as a breakfast food, snack, or may feature at festive meals.
1.Heat 1 tablespoon of the oil in a large, deep frying pan over medium heat. Cook onion, stirring, for 5 minutes or until soft. Add garlic and beef; cook, stirring, to break up lumps for 5 minutes or until beef is browned. Stir in paste, sauce, canned tomatoes, stock and thyme; bring to the boil. Reduce heat to low; simmer, partially covered, for 45 minutes or until thickened. Season to taste. Cool.
2.Preheat oven to 200°C/400°F. On a large piece of baking paper, layer fillo sheets ontop of each other, brushing with some of the remaining oil between each layer. Spread mince sauce over one half of the pastry leaving a 3cm (1¼in) border. Evenly top with haloumi and spinach. Fold pastry over filling, folding over edges to secure. Slide pastry on paper onto a large oven tray. Brush pastry with a little more of the oil then sprinkle with extra thyme and freshly ground black pepper.
3.Bake borek for 25 minutes or until golden and crisp. Cut into pieces and serve with kale leaves and lemon wedges.
Borek is best baked just before serving. The beef mixture can be made 2 days ahead; store, covered, in the fridge.