One is not allowed to say certain brachas in the middle of bircas krias shema (even "between perakim" -- between certain parts of Bircas Krias Shema.) For example Asher Yatzer, or the bracha on a tallis (according to the Ashakanazim) for one that didn't have a tallis from before. If a person by mistake would begin to say either one of these brachas (or any bracha that can't be said in the middle of bircas krias shema) what should they do (in any of the following scenarios)?
"Baruch Atah HaShem" and then remembered
"Baruch Atan HaShem Elokeinu Melech Ha'Olam..."
"Baruch Atan HaShem Elokeinu Melech Ha'Olam asher..." (or even continued and said more of the bracha on a tallis or asher yatzer.)
Should they end off the bracha? Should they stop completely (no matter where they are?) Should they stop and say "Baruch Shem Kavod Malchuso"? Should they end off with something else (for example "lamedene chukecha")