The intransitive use of 'enjoy' is now extensively used by semi-literate restaurant staff in Britain too.

I agree with the OP that English greatly lacks a suitable term for enjoining your dining partners in the way that 'bon appetit' does in French.

But English, across the centuries, has overcome natural deficiencies, by simply borrowing a foreign expression. Are there really many people in America who wouldn't understand what 'bon appetit' meant? I alternate it with 'Guten appetit'. But doesn't Spanish have an equivalent which Americans might use?

The intransitive use of 'enjoy' is now fairly extensively used by restaurant staff in Britain too.

I agree with the OP that English greatly lacks a suitable term for enjoining your dining partners in the way that 'bon appetit' does in French.

But English, across the centuries, has overcome natural deficiencies, by simply borrowing a foreign expression. Are there really many people in America who wouldn't understand what 'bon appetit' meant? I alternate it with 'Guten appetit'. But doesn't Spanish have an equivalent which Americans might use?