The phrase "slice bread" means something that is very easy and useful, like when slicing bread with a knife - it's simple and helpful.
Sentences with «slice bread»
Well I shouldn't assume everyone loves it but it is one of the best things since sliced bread in my opinion! (freespiritedsisters.com)
Cut two pieces of sliced bread into cubes then combine in a bowl with olive oil, salt, and thyme, stirring to coat evenly. (veggieandthebeastfeast.com)