Put the flours, salt , seeds and yeast in a mixing bowl, or food mixer with a dough hook.
Add the porridge and tepid water. Mix the ingredients well with a metal spoon, or with the dough hook for about 5 minutes until thoroughly mixed but still quite sticky.
Cover the bowl with cling film and leave to rest until it has roughly doubled in size, for about an hour.
Turn the dough out on to a floured surface and knock it back, kneading for about 5 minutes until smooth and light or using a mixer with a dough hook, knead it for about 4 minutes.
Shape the loaf and place into a greased 900g loaf tin. Cover with greased cling film or a tea towel and rest for 40-45 minutes.
Heat the oven to 200C / Gas mark 6
After resting, the dough should have nearly doubled in size.
Sprinkle the oatmeal over the top and bake the loaf for 40-45 minutes until cooked through. Check by turning the loaf out of the tin and when tapping the bottom there should be a hollow sound.
Turn out on to a wire rack and cool before cutting.
Notes
I like to slice the loaf and pop it in a plastic bag into the freezer, ready to toast from frozen.