Believe it or not, I actually played a Monk 2/Sorc 1 not all that long ago.
Long story short, we were making characters for a oneshot and basically everybody independently decided to run Monk, as we don't have a lot of those at our table normally. The party ended up being three Monks and a Barbarian. Naturally, that left us in need of spellcasting in general and Charisma in particular, so I thought, "how can I get 14 Charisma while still being the most effective Monk I can pull off at this level?"
Between the DEX/CON/WIS that a Monk already wants, I figured at this level WIS was the weakest link, as it contributed mainly AC and not much else yet, so I went for 13 WIS 14 CHA. I could then take a level in Draconic Bloodline Sorcerer to have my AC be 13+DEX (so equivalent to a 16 WIS Monk), and I also made that my first level so that we weren't all good at the same saving throws either. I went vhuman to get Gift of the Metallic Dragon for a defensive reaction and a way to know Cure Wounds for emergencies, and then took a bunch of utility cantrips, Shield, and Grease.
I played him as a gritty cowboy wanderer type, think the Man With No Name, but also having had something happen to him that made him a little supernatural as well.
Anyway, the oneshot ended up being two oneshots with a third on the way, and we'll be level 4 next time (I took Ascendant Dragon Monk, gotta stay on theme--Mercy would probably be best though, partially because its Wisdom reliance is minimal on top of the usual reasons Mercy is good), so we'll see how that pans out.