(as) different as chalk and cheese

/az dˈɪfɹənt az tʃˈɔːk and tʃˈiːz/

/æz dˈɪfɹənt æz tʃˈɔːk ænd tʃˈiːz/

not in any way alike in character or quality

Examples

1. and I were like chalk and cheese.

2. It's safe to say that Lisa's night job and her day job are as different as chalk and cheese.

3. It's safe to say that Lisa's night job and her day job are as different as chalk and cheese.

4. They might look different as chalk and cheese but both face the same issues at the end of the day.