The flavor of whole sesame seeds isn't released unless they are heated to very high temperatures. If McDonald's cooks the seeds on the buns, which they may not, I'm sure they don't bake the buns hot enough to release the seeds' oil. You really have to heat those guys up to make them good. Usually, when the seeds are served with sushi, they are seared or toasted first.
If anyone wants to try it, you can make a damn good sesame tuna dish by marinating tuna filets or chunks in soy, ginger, and wasabe overnight, coating the fish in sesame seeds (much like you would breading) and then searing everything over an intensly hot fire for about 20 seconds on each side. The fire should be around 500 degrees and the fish should only be a few inches from it. You should end up with fish cooked about a quarter inch in on each side of the chunk and delicious, raw red tuna through the middle. The intense heat releases the magic of the sesame seeds, you serve it with wasabe and rice, and you have yourself a nice dinner.
By the way, I really like cooking.
