• Heat the oil in a frying pan over a moderately high heat and fry the onion until soft, add lamb, garlic, chilli flakes and tomato paste or purée. Stir gently until combined.
• Cook for 5 minutes, adding a little water if necessary, but the mixture must be dry. Season and stir through spinach, spring onions and Feta. Set aside to cool.
• Preheat the oven to 200oC, 180oC Fan, Gas Mark 6.
• Take a sheet of filo pastry and lay on a chopping board. Brush with the melted butter and top with another layer of filo pastry. Cut into 2 strips, lengthwise. Keep the remaining pastry under a damp tea towel to prevent drying out while you work. Repeat until you have 12 strips of double-layered filo pastry.
• Place a spoonful of lamb mixture at the end of each strip. Fold a corner of the pastry across to form a triangle. Continue to fold in a triangular fashion until you reach the end of the pastry strip. Brush with melted butter to seal the edges.
• Repeat with the remaining filo pastry and filling until you have 12 triangular parcels. Brush with a little more butter then transfer to a non-stick baking sheet. Bake in a hot oven for 10-12 minutes.
• Meanwhile, to prepare the dip; in a small bowl, mix all the ingredients together.
• Serve the samosas with the dip.