I recently reheated up in my oven – baked chicken shnitzel and tuna steaks in separate uncovered pans in the same (meaty) oven at the same time.
Before we ate it, a friend told us that “everything is now assur” as it’s a sakana to cook meat and fish together, and it’s worse than issur. But I always thought that that was only by meat and fish, and not chicken, and also only when actually cooked together.
Can we eat them or is everything now treif? do I have to kasher my pots and oven?
Both dishes are permitted to eat. Of course, there is no concern over the pots and oven.
Although the Gemara (Pesachim 76b) does imply that it would a problem, even bedieved, to cook meat and fish together in the same oven, the fact that this halachah is not ruled by Rif or Rambam has led poskim to be lenient. Although we continue to be careful not to eat fish and meat together, many authorities are lenient concerning fish or meat that absorbed the taste (alone) of the other.
For lenient opinions, see: Issur Ve’heter 39:25, as cited in Rema, Yoreh De’ah 116; Shach, Yoreh De’ah 116:1; Taz, YD 95:3; Darchei Teshuvah 116:16 (quoting from several authorities); Ha’elef Lecha Shlomo 312. For more stringent opinions, see Peri Chadash (116:4); Peri Toar (116:3); Chochmas Adam (68:1).
Lechatchilah, one should not cook meat and fish in the same over, but bedieved, one may rely on the lenient opinions.