If you purchase a package of mixed greens, a couple of lemons and a bottle of extra virgin olive oil, you can make salads to start your dinner every day. Then you can add sliced cucumbers, tomatoes, radishes, zucchini, scallions, whatever both of you like, to vary the salads..
That is easy and healthy, for starters. And if you start your evening's eating off with a salad, you will not be quite as hungry when the main course is ready, so you will be likely to eat a bit less.
There are so many places to go on the web for ideas for healthy eating. Have you tried googling "Easy, healthy dishes?" You could try that phrase not only at google, but at epicurious.com, foodnetwork.com, foodandwine.com, saveur.com, gourmet.com and probably a whole bunch more.
Please come back and let us know what you've found, and what you're cooking!