What are things to say when you finish eating at a small sit-down restaurant to express gratitude?

I noticed that whenever I eat at a small sit-down restaurant that has 1 or 2 cooks behind the counter, some of the customers will say something short to them after eating – I presume to express gratitude.

I never end up managing to catch exactly what they say though to use for myself. One of them today said something along the lines of “きょうじょう様” but my dictionary doesn’t have an answer for that that I think is correct.