Note enclosed, what enables one's first look? (6,6)

I haven't cracked this one yet — but the brilliant team at Times for the Times have:

LETTER (what enables) + first letter of One (… ‘s first) + PEER (look), with N (note) contained within (enclosed). &lit. I figured out the ‘letter’ bit early on, but thought it would be the second word for ages, and I mean ages.