In the US it’s not crazy for kids maybe as young as 6 to make themselves sandwiches like a PB&J/Ham & Cheese either if parents have an emergency, or to take to lunch for themselves because parents didn’t have time. (Or you know, they’re neglectful)
So is there a go to food for children to make in other cultures?
Traditional Danish lunch is rye bread with a variety of spreadings, sliced sausages and patés. Think of a simpler kind of smorgasbord (depending on the content in your fridge). There’s a lot of traditional combinations all based on a thin sliced rye bread with butter, the main spread and often one or two toppings that go with the spread.
The kids learn to make these kinds of “sandwiches” in kindergarten, and it comes in handy when they get older and come home from school hungry.
It makes for a more varied choice than toast or jam sandwiches.
Examples: https://imgur.com/a/ZgGGUhy
There’s no rye bread with herring in your photo, the Danish don’t eat that? The Dutch do, topped with some chopped onions. Though my kids don’t like rye bread, it is getting old fashioned over here.
Curry-pickled herring with raw onion and caper on rye is the first dish served on our traditional Christmas lunch. Served with snaps.
Fish generally don’t go to well in a lunchbox. The most common are mackerel in tomato with mayonnaise and cod roe with rémoulade, but most kids would frown at it. Also, it requires a fork and knife to eat. The traditional lunch box sandwiches are made to be eaten by hand.
I just found some random photo from the web. Apparently it’s difficult to find a photo of our common lunchbox hand-served-rye-bread-open-sandwiches. Most are of restaurant high topped “smørrebrød”, which also requires knife and fork.