Pretty much the second part - humans are a branch of theirs, and their world is largely Earth-like but a bit hotter and more deserty. It's like the idea behind SE Asian food being spicier than French food, or US Southern food being more oily than Californian fare.

They are more tolerant of extremes in general, and through some weird circumstances are basically the only large animal on their planet, so they are more vegetarian and have cultivated a lot of proteinaceous plants. Spices and added flavor in general are a big part of their process. They have spicy, savory, and sweet foods too, but everything is just shifted one or two notches more sour.

As a result they really love fermented, citrus-based, and vinegar- heavy foods when sampling earth cuisine. An example of a dish they might make in Earth-terms might be like beans with extra lime-juice, brown rice with rice vinegar, nopales tacos with a strongly vinegar-based hot sauce, and orange juice or lemonade.