The Shulchan Aruch (YD 118:1) rules that without a full time Mashgiach to verify integrity: meat, fish and wine must be secured with two Simanim (tamper evident indicators of integrity). Cheese requires but one Siman. Kosher foods delivered by those who are Halachically unreliable, require such Simanim to establish their Kashrus.
see this, from Rabbi Y D Levy
Restaurants, caterers, and fast food stores, particularly those with meat products, require full-time supervision. The Mashgiach must control access to the cooking area, the meat, and the dishes. Supervision that relies on unscheduled visits is insufficient.
A restaurant without a full-time supervisor, operated on Shabbos (customers ordered and paid for their meals before Shabbos) would violate Shabbos by cooking for the next day after the Kosher supervisor left.
The non-Jewish cook used non-Kosher ingredients, even adding butter to the meat dishes.
Recently, a butcher store in Flatbush, N.Y., owned by a well-known religious Jew, was found to be selling non-Glatt meat as Glatt. The local supervising agency had followed the lenient policy of supervising only with Yotzeh VeNichness, random spot checks.
Well-known experts in the field of kosher unequivocally agree that any establishment serving meat must have a full-time, independent supervisor. Most kosher agencies have already undertaken this policy, and we call on all agencies that have not done so, to seriously reconsider their policy and provide truly reliable certification.
Kosher meat is:
at least twice as expensive as non-Kosher meat,
indistinguishable from non-Kosher meat,
easily substituted with non-Kosher meat.
Same is true for "special Kosher" milk and cheese, Chalav and Gevinas Yisrael
Insects are not Kosher.
Vegetables prone to harbour insects must be thoroughly cleaned and inspected to ensure they are clean
Such cleaning and inspection greatly exceeds the usual standards required for food establishments
This is a time consuming, costly exercise
How can a Kosher certifier ensure the integrity of Kashrus, in the face of great temptation of significant profits and weak, ineffective safeguards?
The problem is compounded by the fact that unlike any other forgeries or substitutions of valuable or branded products that always carry some distinguishing qualities and are very difficult to accurately and cheaply copy, and therefore always carry the risk of eventual detection, Kosher meat is utterly indistinguishable from non-Kosher meat.
Halacha [and common sense] has traditionally required constant and continuous supervision by an independent and thoroughly reliable Kosher supervisor.
Melbourne and Sydney Cafe/Restaurants however, have critical Kashrus flaws.
KAM [KA Melbourne] concedes that it certifies meat restaurants, owned and operated by Yidden who are not Shomer Shabbos yet does not have full time supervision. Rabbi Gutnick indicates that KAM [KA Melbourne] under his direction, rely on sporadic impromptu inspections and possibly remote electronic surveillance. He has not yet provided Halachic foundation supporting such procedures and to the best of our research, there are no other Kosher organisations employing or prepared to admit they are employing, such procedures.
Kosher supervision must ensure or at least dissuade regular on-going substitution of very expensive Kosher foods and ingredients, with far less expensive, and indistinguishable, non-Kosher alternatives. Random visits by a Mashgiach is inadequate, there is nothing for the Mashgiach to detect and nothing to be observed that will reveal or suggest that indistinguishable, non-Kosher substitutes are being used.
Similarly, remote electronic surveillance is utterly inadequate to prevent the profit making substitutions. On the contrary, it fosters an utterly false sense of confidence that only encourages the Kosher supervisors to be slack and the proprietors to indulge.
How did it work with Babell Cafe?