ngoih maaih būi
外賣 means takeout, and 杯 is cup (or glass or mug).
杯 is also the measure word for drinks. For example, 一 means one, so to order a glass of water, ask for 一杯水 (yāt būi séui in Cantonese, yī bēi shuǐ in Mandarin), one cup of water.