Preheat oven to 200 C / Gas 6. Lightly grease a Swiss roll tray.
Melt 30g butter in a frying pan and gently cook and stir onions and garlic for about 3 minutes. Add tomatoes and cook for approximately 10 minutes, until soft and pulpy. Stir in vinegar, sugar and basil and cook gently until mixture thickens. Season to taste and cool completely.
Melt remaining butter. Unfold sheets of filo and brush each sheet with butter and layer half together. Spread with 3 tablespoons sun dried tomato purée, then spread half the tomato mixture on top. Sprinkle with half the cheese.
Repeat, layering remaining pastry on top. Roll up from the long end. Place on tray with pastry seam underneath. Brush the outer layer with butter.
Bake for 35 minutes. Cool for a few minutes before serving or serve cold.