Place the rolled oats into a dry frying pan over medium heat and toast until lightly browned.
Mix the dry ingredients, including the yeast, in a large bowl then add the beer and stir to combine.
Turn the dough onto a floured work surface and knead for 10 minutes, using a scraper to lift and turn the dough.
Roll the dough in a little of the oil and set it aside in a warm place until it has doubled in size.
Heat the remaining oil in a frying pan and gently fry the onions until caramelised – this will take about 40 minutes. Set the onions aside to cool.
When dough has risen, knock it back on a floured work surface and knead in the cooled onions and the cheese. Form the dough into a loaf shape, place it on a greased baking sheet and set aside for one hour to prove again.
Preheat the oven to 180C/350F/Gas4. Dust the loaf with a little more flour, cut slashes in the top and bake for 40-50 minutes or until the bottom of the loaf sounds hollow when tapped.