I am pretty sure most of the japanese cooking isekai mangas written by japanese people prefer to highlight japanese foods because their audience are japanese so using japanese dishes helps make the story more relatable to japanese people. As you can tell by the obvious not so hidden messages you probably see what my point is. This helps the immersion for them so they are in the place of the mc who was originally japanese thus missing their homeland's food and they seem to usually pick the common/simplistic dishes that are easily recognizable. Although I have yet to find one where the MC makes latin food, sometimes American, Indian, Euro etc. but never Latin.