Dear Rabbi Simon,
We have just bought ourselves a gas barbecue and are looking forward to using it. I know that we avoid eating meat and fish together (though I’m not sure why). Are we able to cook meat on it one night and fish the next or would that be an issue?
Thank you for your practical question. The Talmud asserts that there is an (undefined) health risk associated with eating meat and fish together. This is why one should eat or drink something in between eating these two food categories. This is also why we avoid using the same utensil for fish and then meat—unless it is cleansed in between.
To answer your question: In principle you may do this if the grill is cleaned in between. However, since this can be difficult to achieve, in practice you may need to wrap the fish in aluminium foil or kasher the barbecue in between by cleaning it as much as possible and then turning to max heat for 45 minutes.
Enjoy—and let the sun shine.
Rabbi Rashi Simon