It depends where you live (I'm in Bangkok, so grocery choices are quite limited).
I love Oats. I got massively back into them again this year... now I buy around 3kg every month (instant oats).
It's only this year, really, that I discovered that oats are still really good and creamy when not made with milk... and it's really easy to boil a single cup of water to dump on a cup of oats for a perfect breakfast (left standing for a minute - done... no need to 'microwave' oats).
Also, cheap staples include: carrots, potato, broccoli, spinach...
Frozen strawberries are dirt cheap here too.
Breakfast 1:
- Instant Oats (1 cup, 1/4 tsp salt, 3tsp sugar, 3 tsp creamer)
- pulsed to powder in the blender with a cup of boiling water poured over.
- Blend 100ml milk with 3 strawberries and mix that in.
The beauty of this is (as my son does NOT like stodgy/thick porridge) I can add an extra 100ml of milk to his breakfast, and it becomes a liquid smoothie.
Breakfast 2:
- Weetbix are not too cheap, but ONE biscuit mixed with ONE cup of oats is a massive breakfast - and tastes of Weetbix... and is ridiculously cheap in comparison.
Breakfast 3
- Oats work great with eggs...
- 1 cup oats, some salt, some cumin (maybe a teaspoon)
- 2/3 cup boiling water (soak a minute)
- 2 duck eggs mixed in
- butter up the frying pan and dump it in there, cover and cook gently for 3 minutes, flip and give them another 3 minutes.
DIsgusting poopy one
- 2 teaspoons of cocoa powder mixed with 4 teaspoons of non-dairy creamer + 1 cup oats
- pulse to powder, add a cup of hot water.
That's choccie heaven right there.