Ah, this is often misunderstood. If we look at the histories, we can see that Lamuella had the sandwich technology well before the arrival of Dent. In fact he was never meant to land on Lamuella at all and only arrived after a hyperspace crash.

Whilst Dent was on NowWhat he was recomended to go to Lameulla by a relocation officer after Dent said he'd like a place with humaniods, sandwiches and freedom.