Haha I always used to think that about nursery too.
18month old generally eats a mixture of:
Breakfast: porridge, weetabix, cheerios - with a bit of fruit in there somewhere or peanut butter
Lunch: sandwiches, omlette, beans on toast, toastie, picky plate made of ham, cut up veg, rice cakes etc, leftovers from night before
Dinner: spaghetti Bol, lasagne, sausage and veg, salmon and veg, chicken goujons, chilli con, pasta pesto, fish fingers, waffles
I freeze/fridge our leftovers for him and bulk cook things and freeze most of this to save time. I also make up spinach and sweetcorn muffins, veg fritters, carrot parsnip and cheese muffins so if I can't be arsed or have no veg in I know he'll eat that, they also make good snacks.
Snacks are rice cakes, fruit, raisins, crisp things.