One honest note. If the couple ask about ingredients or dietary suitability, point them to the published product information rather than answering yourself.
Gifts for men run into the same tired shortlist every year, and flowers rarely make it onto it.
Lily O'Brien's Ireland chocolate does a better job than its reputation suggests, provided you pick the format with the recipient in mind. For most men and most occasions, a large mixed collection is the sensible answer.
A personalised touch suits the occasion well. A message marking the years of service, or simply the leaver's name, turns the hamper into a keepsake of the day rather than a generic box. Keep any message warm and brief, allow lead time for the personalisation, and order earlier still if the retirement falls near Christmas.
Then there are the larger thank yous, a promotion helped along by a mentor, or a significant favour, where a fuller collection is appropriate. Match the size of the gift to the size of the gesture and you rarely misjudge it.
For more detail, see share bag chocolates.
Presentation helps the impression. A neutral, well-put-together box needs no wrapping and photographs well if the new owners are the sort to post about the day. It also avoids the guesswork of matching a gift to a colour scheme you have not seen yet, which is the risk with anything decorative for a home.