How can we do evaluation few-shot in Chat-template?

[srn-source]

prompt = """<|im_start|>system
You are a helpful assistant.<|im_start|>user
Qus1;.......<|im_start|>assistant
Ans;1.............<|im_start|>user
Qus;2.......<|im_start|>assistant
Ans;2............."""

or

prompt = """<|im_start|>system
You are a helpful assistant.<|im_start|>user
Qus1;.......<|im_start|>assistant
Ans1;.............

<|im_start|>system
You are a helpful assistant.<|im_start|>user
Qus2;.......<|im_start|>assistant
Ans2;.............
"""

lm-evaluation-harness didnt support the first format when i do few shot they support on second format that why i am not sure which format are used when eval Chat-template (Chat Model) ?

I don't know how we do it theoretically. Somebody can help me?