When I've got nothing out for lunch and leftovers are lacking, I often go for this surefire winner:
Baked Bean and Cheddar Quesadillas
Open a can of your favourite baked beans and grate some of your favourite cheese (I usually have old Cheddar on hand). Mash beans onto one half of a whole-grain tortilla, sprinkle with cheese, fold over to create a half-moon and press firmly. Repeat as many times as needed (two tortillas means four to six wedges for mom and two to four wedges for toddler). Cook in a non-stick fry pan (preferably cast-iron), on a griddle (my favourite), or bake in the oven until tortilla is crisp and the cheese is melted (5-10 minutes). Cut each half-moon into four wedges and serve. You'll have beans leftover for a snack, or for the same lunch tomorrow.