Ah, right, just looked up the EU socket design. It's already recessed, which means the plugs have to be longer to account for the recess, and it means you can't recess the whole socket enough to get the plug al the way into the wall without an extra deep wall.Ehh, possibly. it's the divider wall with the apartment next door though, I'm not sure how much deeper I can put the cables witohut ending up in their kitchen.
I think you're right, directly wiring it in is your best option. Make sure you have a proper cover with a bushing for the wire and you'll be fine.
The plugs are large and heavy enough that you can use the plug and leftover wire as a basic flail type weapon, and unlike knives and guns you won't be questioned by police if you walk around with one. Things, apparently, aren't always bigger in Texas!
I still envy you your 3kW countertop kettles, though.