My current go to for the past few years is oatmeal. I mix oats, dry milk powder, frozen cherries, and water. Then I throw it in the microwave for a few minutes to cook. Once it’s done, I add cinnamon and a handful of chocolate chips and mix it all together. It’s probably not the most healthy option, but it’s tasty and reasonably nutritious.
I recently started tracking what I was eating for nutrition/weight loss purposes and realized I should be eating way more protein. I’ve tried protein powders in the past (a lot of online recipes for oats recommend adding protein powder) and hate how strongly they are flavored. I saw a lot of diy protein powder recipes have a base of dry milk powder which I already had in my cupboard, so I just use that. It’s fine with the same amount of liquid.
You could just use normal milk instead of milk powder + water, but this was lower calorie and never goes bad.