"You practice cooking rice."
Translation:Bạn luyện tập nấu cơm.
ăn = eat. Nấu ăn = cook to eat. In another work, cook for the purpose of consumption. Nấu cơm = cook rice. So you can see squeezing ăn into the middle of it would be weird because now it means "cook to eat rice." You can however says "nấu cơm ăn" = cook rice to eat. But if you practice, then you just practice cooking, not eating too :-)