What are the kashrut issues with kosher food at a non-kosher restaurant?

Question

What are the major kashrus/halachic issues with going to a non-kosher restaurant and ordering, say, [kosher fish] and vegetables; dressed with only extra-virgin olive oil, salt and pepper; double-wrapped in tinfoil and baked, served on paper plates with disposable cutlery--a dish which would seem reliably kosher under many circumstances?

I can think of the following potential problems. I am wondering if each of them in fact applies to the situation, or if there is room for leniency within any of them. I am also wondering if there are any I have missed:

• Maarit ayin/chashad: Giving the appearance of doing something improper by ordering at a non-kosher restaurant.

• Lifnei iver: Potentially misleading Jews that the restaurant is kosher and thus causing them to sin by eating there.

• Bishul akum: Potentially eating food that is treyf insofar as no Jew was involved in the cooking.

• Questional ne'emanut of non-Jews - There is an idea that we don't say ed echad for non-Jews; that is, that we cannot trust the supervision of those who are not themselves observant (or at least obliged) in kashrus and/or Shabbos. We can't watch the kitchen and thus cannot know that the waiters/chefs are actually doing what we said...and there is no halachic basis on which to trust their word.

• Questionable kosher status of the knive(s) used to cut the salmon and vegetables. This would be of particular issue if the salmon were cut while hot, and/or if any of the vegetables were davar charif ("sharp"). (If the food were not sharp, but only hot, I could see this as possibly falling under a leniency for stam keilim einan b'nei yoman.)

• Possibility of (very small) bugs in the vegetables, since even nice restaurants do not necessarily check to halachic standards.

...Can anyone comment on these, or add?

(Motivated by this advice on eating kosher on a cruise line--in particular: "I was advised by my Orthodox rabbi that it is permissible to have the chef cook double-wrapped fish and vegetables in the oven as long as the knives are clean and nothing is added to food.")

Answer 1

I think you're missing the most important issue:

The pots been used to cook the food may have recently been used to cook unkosher food - and thus render the food unkosher.

While we normally assume that pots are not ben-Yoma (i.e. have not been used in the past 24 hours and hence don't make the food unkosher) in a restaurant that assumption is clearly untrue. Most pots are in constant use, or they are not thoroughly washed between one serving and another.

If the issue were merely the knives, once could possibly cut off a sliver where the cut was made. But if it's cooked in an unkosher pot, then the entire food is unkosher.

Pots (or pans, etc.) would be unkosher for various reasons. E.g.: if unkosher foods were cooked in it, or if meat & milk (of kosher species) were both cooked in it within 24 hours of each other.

Same issue would be with any utensil that touches the food; whether the utensil is hot or whether your food is hot; the unkosher utensil could make the food unkosher.

So even if the food is cooked - for example - wrapped in baking paper - if at any point the actual food is touched with the cook's utensils while either is hot, it would be unkosher. (Assuming the cook doesn't use disposable utensils that are changed for every dish.)

Answer 2

According to Rabbi Yitzchak Abadi, there is no issue with Maarith Ayin. Here are some quoted examples and responsa. Some of these responsa are from his son A Abadi.

Example 1:

Questioner: How can you compare a treif restaurant where people go to eat treif to an airplane that serves kosher meals, also the kosher meal is clearly distinct to those who look at it. I am curious, give me an example of what according to you would constitue [sic] maris ayin. BTW, thanks for your time, continue your service to Klal Yisrael. Howard

A Abadi's Response: Quote "the kosher meal is clearly distinct..."

and my tuna sandwich looks like a burger?

If a community does not know of Pareve (non-dairy) milk and you cook your meat in a non-dairy milk type product that you brought from your travels abroad. When the people see you cooking meat with milk or eating meat that was cooked in what they perceive as milk, that is maarit ayin! AA

Example 2:

Questioner: Could you list diffrent [sic] things that are a problem of maarit ayin? Thanx

A Abadi's Response: There aren't many things that apply today, because of our Globalization. Everything that we do can be explained as a commonly available alternative that is Kosher or allowed.

For example: If someone cooks meat with milk, we wouldn't have to assume that he is doing a sin, we can say the milk is really "non-dairy," as is readily available.

If someone eats in a non-Kosher restaurant, we can assume he is eating those items that are OK.

If a person puts food in the oven or his air conditioner goes on in the middle of Shabbat, we assume that he has set them on timers.

On the issue of non-dairy milk the Kreity UPlaity says that Maarit Haayin does not apply if an alternative Kosher or permissable [sic] item is common, as in the above examples. The person who sees another eating meat cooked with milk can easily assume that this was "non-dairy" milk and the person was not doing any sin. The Halachah that prohibits it is only in places or times when non-dairy milk was scarce. AA

Example 3:

Questioner: Aren't you concerned about Marat Ayin? (please don't simply write no, rather, explain yourself)

A Abadi's Response: The Gemara lists the specific cases where maarit ayin applies. We are not permitted to make new scenarios. If we were allowed to, it would never end. You cannot go to Las Vegas for a trade show. You cannot drive in certain parts of town. You cannot pick up your sister from the train. etc. etc. etc.... AA

Answer 3

HaRav Yitzchak Abadi, who is known for being lenient on kashrus matters--whose piskei may apply only to Sephardim--seems to think that the main problem is bishul akum. If bishul akum can be avoided, he says one may eat there. He provides specifics of what may be eaten, including breadsticks, vegetarian soup, and desserts.

Please be aware that this ruling, and Rav Abadi's kashrus rulings in general, are significantly more lenient than the mainstream.

Related: Which rabbis permit food being kosher just based on the ingredients?