Preventing a qualified candidate from getting a job or promotion because of bigoted views of their race. Verbally harassing an individual after learning about their religious beliefs.
An idiot who can't keep their mouth shut and yells slurs on public or posts them on social media, even though they are socially not allowed to
Bigot: "back in my day, fags were beaten up"
Normal person with actual empathy/sympathy, aka BASICFUCKING HUMAN DECENCY: "that's what's wrong with the world."
The term originates from The Last of Us 2, where a character that said something bigoted to Ellie, one of the protagonists, and made her steak sandwiches as an apology. In the same scene she passes the given sandwiches on to another character, who reacts positively to the gift.
In short a "bigot sandwich" can be defined as "a sandwich with steak".