Why sesame seeds?
I have particular aversion to sesame seeds. My reason is too indelicate to go into here, but if you google "enterobius vermicularis egg" you may understand.
I'm finding these seeds sprinkled on almost everything. I've heard they impart a "nutty taste" but I don't register any taste. I see them as adding cost without benefit to rolls, breads and some Chinese dishes.
Can someone tell me what sesame seeds are supposed to add to food?
They add some flavour, especially when roasted and add some texture to a dish if added as a "seasoning"
The roasted sesame oil is very concentrated and will add a lot of flavour to a dish (some times too much)
nothing more, nothing less.
I use them for the flavor, especially when you toast them prior to adding to the finished dish. But I feel your pain; a guy who used to work for me suffered from a condition that made seeds and nuts verboten.
Our waiter at a restaurant in Hawaii, years ago, wrote out a recipe for one of their delicious salad dressings. Very generous.
The recipe calls for black sesame seeds. I've tried making the dressing without them, because I was out of them, and the dressing didn't taste the same.
They're very tasteful and they add texture.