The performance indicator being covered is Standard ESL2- Language for Literary Response and Expression. Students learning English as a second language will use English for self-expression... and participation in popular culture. This standard can be achieved by learning idioms and how to use them in everyday language as well as understanding them when native speakers are talking.
I would test this by talking about the idioms in small groups about the idioms and making definitions of what they think the idioms mean. I will then take a look and clarify if needed. Then I will have the students make a dialogue in class and perform the dialogue in class in front of their classmates who will interpret the use of the idioms and if they were used properly or not.