Savoury mixed vegetable porridge

SOURCE This recipe is a Seven Acres take on a time-honoured Winter warmer.
Serves 4 as main breakfast course
Time (approx): cooking 15-20m (but see 'Advance Preparation' below)
NOTE This meal is most easily managed if you cook the vegetables the day before, but it is perfectly possible to make it all in the morning: just allow an extra half hour or so.

150g mushrooms
c.120g onion (unprepared weight — a medium-sized onion)
120g carrot (unprepared weight)
1 tbsp olive or vegetable oil
You can change the amounts and substitute/add (e.g. celery) to your heart's content.
190g porridge oats*
1 litre water
3-4 tsp Seven Acres vegetable stock concentrate**
* When treating ourselves, we use the magnificent local organic gluten-free oats from The Merry Mill
* Or season to taste with salt, pepper and herbs such as thyme or rosemary.
Knife with a sharp blade
Wooden spoon or spatula for stirring
Vegetable peeler
Medium saucepan
Weighing scales
Measuring jug
A hob or other direct heat source for cooking; Space to chop.
Advance preparation
Cook the vegetables the night before, so that they will be ready for making the porridge for breakfast the following morning.
Preparation time 15m; cooking time c.20m.
Preparing the Vegetables
Cut the mushrooms into small dice.
Peel and chop the onion.
Peel and cut the carrot into small dice or thin slices.
Cooking the meal: Part 1
Heat the oil in a saucepan; add the chopped vegetables and sweat over a low heat until cooked.
Cool the cooked vegetables and store in a container in the fridge overnight.
Part 2
Put all the ingredients — oats, water, cooked vegetables and stock or seasoning — into a saucepan; stir well and bring to the boil.
Turn the heat down to low and let the porridge simmer until it is cooked to the desired consistency, stirring occasionally to prevent it sticking to the saucepan.
Serve in pre-warmed bowls.
Suggested accompaniment
This needs nothing other than a good cup of tea to make a perfect start to a cold day!