I totally agree. I'll go further saying I would think of food in general/meal before rice if being told about "nấu cơm" or "ăn cơm".
second point I want to mention, "luyện tập". practice is sometimes translated as "luyện tập", sometimes just "tập". from my own interpretation of it, "luyện tập" is having a practice that demands more determination, effort, concentration. "tập" seems more like a routine practice.
I think your translation might be too loose, not close enough to how the original sentence is formulated.
but shouldn't this be continuos then? If it's really "practice cooking" shouldn't there be a "đang" included in the vietnamese sentence?
no, "cooking" is not here the present participle, from the continuous tense be cooking. instead it acts as a gerund, the nominalization of the verb cook.