Here is one for you that I think they would like.

This recipe from Real Simple claims to feed 4 but it is more like 6-8 and I leave out the spinach.

http://food.realsimple.com/realsimple/recipefinder.dyn?action=displayRecipe&recipe_id=1123648

Also try something a bit different. I like grilled peanut butter sandwiches or grilled PB&J instead of grilled cheese. Just a different spin on something that is inexpensive and yet relatively healthy (especially if you use wheat bread).