A thing I like to do is slow cook stuff which I can freeze for later. The freezer that came with my fridge is always running anyway, and it's more efficient the more it is filled with useful stuff.
Stews, chilis and soups are all awesome and you can find a ton of slow cooker recipes, but also it's very easy to just cook up a bag of beans overnight and use them for whatever. I cook a bag of garbanzo beans, process it into hummus the next day, and freeze it all in small containers. It thaws fine, if it separates a little during the thawing process just stir it. Be careful slow cooking certain beans like kidney. These release a toxin if they are never heated above a certain temperature, so it's suggested to boil them for ten minutes before slow cooking. But that's not with all beans, garbanzos for example are fine and IMO come out way tastier than canned.
The slow cooker is generally considerably lower electricity use than what it would take to make the same dish on the stovetop or heating the whole oven. The whole slow cooker to freezer thing can also be freeing from purchasing frozen and canned meals. Just pull something you already made out of the freezer and heat it up.
