Honestly, the every British UK audio I hear for the word "sauce" sounds like "Saws" without pronouncing the S at the end as a "Z" sound. I wonder if it's a dialect?

I'm Bostonian (give or take), so I'm unaware of missing R's most of the time, but hyper-aware of them when I listen for them. British folks say "sauce" similar to how I would. Throwing that R in the trash.