Reference for Pesachim 147:9

אמר רבה האי מולייתא שריא א"ל אביי והא קא בלע דמא א"ל כבולעה כך פולטה

Our Rabbis taught: What is the helmeted goat which it is nowadays forbidden to eat on the nights of Passover?<span class="x" onmousemove="('comment',' I.e., after the destruction of the Temple; v. supra 53a.');">¹⁴</span> Wherever the whole is roasted in one [piece]. If a lamb was cut from it, [or] if a limb of it was boiled, that is not a helmeted goat.

Jastrow