Usually, any type of one pot meal (chili, soup, spaghetti sauce, beans and rice etc.) as well as casserole type meals (lasagna, enchiladas, tetrazinni, etc.) are actually better the next day. Though traditional recipies are high in calories they are easily adaptable to suit a healthier lifestyle.
You might also consider freezing leftovers in individual portions. And if your fiancee cooks at all keeping quick cooking foods on hand may be an option. Shrimp and seafood are good examples. Also, take a look at your current rotation of menus. You may find that some of them can be made ahead which would allow you to cook your portion and refrigerate his to be cooked later. For instance, if you are marinating beef or chicken, it would be easy enough for him to just throw his on the grill or in the oven by himself (of course, I always have to leave instructions for my husband but if you "train" yours now you might not have the same headache down the road! LOL). If you have something like a George Foreman grill it will make it a little easier for him too.
Stir fry's are easy to throw together as well. You could slice the meat and veggies in advance (keeping them seperate, obviously) and all he'd have to do is throw them in a skillet. Fajitas are easily done this way as well.
Take a look at different crock pot recipes as well. I've got one that is really small and just right for throwing in just enough food to serve 2 people (we've got three kids now so I don't get to use it much anymore LOL). Maybe the first person up in the morning could load it up, the person home for a traditional dinner time could eat the first serving and refrigerate the rest for the other person. That could save you some cooking hassles.