For the oatcakes, tip the oats and 350ml water into a bowl and blitz with a stick blender until smooth (alternatively you can use a food processor or liquidizer). Stir in the flour and yeast, cover and leave in the fridge overnight, or leave at room temperature for 2-3 hrs until bubbles appear.

Use kitchen paper to rub 1/2 tsp oil round a non-stick frying pan, then heat. Ladle in a quarter of the batter and swirl the pan to cover the base (the oatcakes should be a few millimeters thick, like a crêpe). Cook for 2 mins, then turn and cook for 2 mins more until golden. Make four oatcakes in the same way. If you're following our Healthy Diet Plan, chill two for another day. Will keep, covered in the fridge, for two days.

To make the topping for two oatcakes, heat 2 tsp oil in a non-stick pan, add 160g mushrooms and fry for 2-3 mins, stirring until softened. Stir in 2 tomatoes, then add 2 tbsp ground seeds and cook for 2 mins more. Reheat the oatcakes in a dry frying pan or the microwave if necessary, then spread each one with 1 tbsp tahini, the mushroom mixture and scatter with a little coriander before serving. On the second day, repeat step 3 with the remaining ingredients.