Preheat the oven to 180C/360F/gas mark 4. Heat the oil in a pan and add the garlic and spinach. Wilt quickly then set the wilted spinach on kitchen towel to soak up any liquid.
Roll out the pastry on a floured surface. Place the raw salmon in the middle, then layer the spinach on top of the fish. Grind over a little pepper. Layer the smoked salmon evenly over the spinach. Now wrap it up. Bring the edges of the pastry over the fish and seal thoroughly by pinching the edges together. Do the same at each end. Trim away any leftover pastry.
Brush the pastry all over with the beaten egg and sprinkle over the cumin seeds. Set on a baking tray place in the hot oven for 25 minutes until nicely golden. Serve in slices with a herby salad or greens.