One trick to remember with eggplant is to slice it ahead of time, sprinkle it with salt and lay it on a paper towel for about 10-15 minutes, turn it over and do the other side, then rinse it before using it.
Or just a straight up vegetarian lasagne.
Macaroni and cheese? Make it special by using a different cheese, edam, gouda, havarti, farmer's cheese . . . Beat a couple of eggs and whisk them into the cheese sauce, quickly, before you pour it over the macaroni and bake it.
Or a rice and cheese casserole, basically the same way you'd make macaroni and cheese, add some chopped vegetables to the rice.