Preheat the oven to 190°C. Grease a medium springform tin with nonstick spray.
1 Crust Put the dry ingredients in a food processor and pulse until the sunflower seeds and rolled oats are finely ground.
2 Add the salt, egg and butter and process until a dough starts forming around the blade. Remove and make a long roll. Slice and line the bottom of the prepared tin with crust, then press down with your fingertips. Chill in the fridge for 10 minutes. Put a smaller tin inside the large tin and bake for about 10 minutes.