You can say "Mom, I'm hungry. Let's have some bread." in Engpsh.
"Mom, I'm hungry" is a common way to express hunger in Engpsh. "Let's have some bread" is a suggestion to eat bread.
The phrase "let's have" is a casual way to suggest doing something together. For example, "Let's go for a walk" means "Let's go for a walk together."
Here are some other examples of "let's have" in Engpsh:
"Let's have a picnic" (suggestion to have a picnic)
"Let's have a drink" (suggestion to have a drink together)
"Let's have lunch" (suggestion to have lunch together)