I cook legumes in bulk and freeze them in individual portions. My usual breakfast is oatmeal and water in a pasta bowl, with the frozen food on top, all microwa

I cook legumes in bulk and freeze them in individual portions. My usual breakfast is oatmeal and water in a pasta bowl, with the frozen food on top, all microwaved together. It all defrosts and rehydrates (rolled oats are sold already cooked) at the same time so it's very convenient. This has more protein than pure oats, but you're right the calorie density is a problem. A bowl of oats cooked as porridge has about half to 2/3rd the calories of a bowl of cooked pasta, depending on how thick you make it. I usually add some butter or olive oil to improve this.