Pick up a copy of Disney's Family Cookbook, great kid recipes! also, you could probably do a search online for some new ideas.
Sometimes we do something fun, like pancakes for lunch or ice cream sundaes for dinner, just to break up the routine. Oh,yea, and they used to love english muffin pizzas, you can let your son help make them. let him roll some of his favorite stuff into a wrap. tacos are another favorite around here. cut your sandwiches into fun shapes with a cookie cutter. maybe an appetizer tray, with cheese, crackers, pepperoni, fruits and veggie sticks. kids love finger foods.
pretend you are camping and make a tent out of sheets indoors, and eat in the tent, or try a picnic on the living room floor!
we tend to get into the same old routine too, so enjoy and think outside the box! hope this helps... God bless!