One meal, and no reason why it should be always you cooking it.
But, that one meal should be proper family food, with a wide range of meat, fish, herbs, spices, vegetables etc, and not constant spag bol, bangers and mash, pasta or other similar kiddy food. It's unreasonable, for example, for your husband to never have fish, just because the children are allergic. A normal, varied menu should be planned (which for most families would include fish once or twice a week at least) and then the children's fish substituted for something else (e.g chicken breast, duck breast, pork chop etc) if the children are actually allergic. (If they just don't like fish, then I'd just take the like it or lump it approach).
IMO, there are pretty much no foods that are not suitable for children 1+, excepting any allergies. So I would (and did) serve meat, fish, salads, curries, squid etc as family meals from the outset. The bangers and mash or pasta and sauce type meals are OK for a speedy one off, but not suitable for every day, for either adults or children.
So he is BU for expecting you to do all the cooking, and for expecting you to cook something especially for him, but NBU to expect a full range of varied food, suitable for adults to be served.