The evening before, place the oatmeal in a large bowl. Add 1 tbsp lemon juice, 1 tbsp whole wheat flour and about 1½ cups warm water. Mix and leave somewhere warm to soak till next morning.
The next morning (or after about 8-12 hours of soaking time), preheat your oven to 180C/350F.
In a large casserole dish, combine oatmeal with all the other ingredients except milk. Mix really well.
Add the milk and stir it in gently. The mixture will become quite thin - that is fine, almost all the liquid will be absorbed as the oats bake.
Bake the oatmeal for about 30 minutes until set and golden on top. Check on it once during cooking to make sure it is not getting too brown on top.
Serve immediately with some warm raw milk.
Notes
This dish can be assembled in the evening and refrigerated overnight, to be baked the next morning.
Or you can keep the soaked oatmeal in the fridge for up to 24 hours until you are ready to assemble this dish.
If you decide to use unsoaked oats, you will need to add extra milk (or water) to this recipe and possibly bake the dish a bit longer. Soaked oats require less liquid (because they have already absorbed quite a lot during soaking time) and are quicker to cook than unsoaked oats.