Is It Permissible to Eat a Sandwich with an Omelet That Has Been Refrigerated Overnight?

Greetings,

It is permitted to eat without concern.

Sources: Although it is indeed forbidden to eat a peeled egg that has been kept overnight, as explained in Tractate Niddah (17a), and codified in Shulchan Aruch HaRav (Laws of Guarding One's Health and Life, section 7), when the egg is mixed with other foods it is permitted, as outlined in the Semak (Siman 181). This is also the ruling of the Ben Ish Chai (Year Two, Parashat Pinchas, paragraph 14), the Kaf HaChaim, Yoreh De'ah (Siman 137, paragraph 212), and the responsa Yabia Omer (Part 2, Yoreh De'ah, Siman 7, paragraph 9), as well as Even Yisrael (Part 9, Siman 126, paragraph 3). Additionally, this was brought in the name of the Chazon Ish, of blessed memory, in the book "Shimrat HaGuf VeHaNefesh" (Part 1, margin of page 25). Similarly, in the responsa Nadad, Yescheil Avdi (Part 7, Orach Chaim, Siman 44, Question 4), it is permitted to eat fried egg that has been kept overnight, since it has been mixed with oil and the like, thereby changing its original status. For further reference, see "Archot Rabbeinu," Part 1 (page 376, paragraph 14), citing Rabbi Yitzchak Kanievsky, of blessed memory, who apparently agreed with the Chazon Ish's ruling.

Best regards,
Hillel Meirs