Alternatives, er, potatoes? That includes chips, roast, boiled, mashed, casserole. Add some ketchup, they won't miss the pasta... what about rice? Brown, white, basmati, rissoto...Boiled egg instead of a sarnie in child lunchbox? Rice cakes with spread in lunchbox? Lentils, pearl barley, quinoa, arame or pulses for tea (admittedly, my children won't eat, but DH & I happily tuck in while they have something else).
Heap up with vegetables and keep the starches a small part of the main meal.
Bread: so many options. eg., You can get rye bread in Lidl that has almost no wheat. It's like wholemeal, though, so go for a rice or corn flour bread if your children wouldn't touch wholemeal.
Corn biscuits (scones) or buckwheat pancakes (American style).
Cereals: porridge, corn flakes, readybrek, rice puffs, puffed millet etc. in health food shop.
My children eat all of that fine, although they love wheat bread, too. I imagine it's very hard to be completely wheat free, but cutting down just seems easy to me.