How can my Cleric gain the Shield spell, and cast it using spell slots?

I am looking to build a order domain cleric, and looking at ways to obtain the shield spell. Specifically I hope I can learn it in a manner that allows me to spend my spell slots on it.

So far I have found the following:

  1. Multiclass – I don’t like this because I am struggling to justify it RP wise, would likely need to take at least 13 points in a dump stat, and it delays my progression, but is the only method I have found that meets my main criteria
  2. Magic initiate – Apparently I can’t use my spell slots so this is 1/day only
  3. Aberrant dragonmark – Counts as a sorcerer spell so I still can’t use my spell slots on it (probably)
  4. Talk to my DM – Unlikely to work because he knows I am a bit of a powergamer (hence wanting the shield spell on top of heavy armour, a standard shield and probably a shield of faith spell too)
  5. Cheat – Just hope my DM doesn’t notice it isn’t a cleric spell or doesn’t know the rules around class spells and spell slots – not my style
  6. Get a magic item (I am not sure there even are any) – this isn’t really an option even if one does exist, because the DM rolls for loot

I can use all legal source books, but have I misinterpreted anything I have above, or missed any options?

Bonus points if someone can find a way that also gets me booming blade 🙂