1: Preheat the oven to 390°F (200°C). Spread 100 g rolled oats in a thin, even layer over a sheet of cooking parchment laid on a baking sheet. Toast in the oven for 10 minutes.
2: At the end of this time (do watch for the colour and don't let them get too brown), take them out of the oven and leave to cool. When cold, blend the toasted oats to a floury consistency.
If, like Louise, you really like the flavour of oats, you can increase the weight and take off the same weight of flour. For an even more rustic flavour, use brown cane sugar.