The dish is defined by a last-minute dose of kaphrao
(holy or hot basil), an ingredient so essential that the dish is
named for it. For short, people often order it as phat
kaphrao, literally "stir-fried holy basil." In the US, we'd
never give top billing to an herb. Dill salad? No, it's egg
salad. Grilled rosemary? No, it's a charred steak so what if
it happens to be perfumed by a few sprigs?
The herb has a very particular flavor, to be sure,
a distinctive peppery heat, but in Thailand, it's prized for its powerful aroma. The notion of aroma eclipsing flavor can sometime confound us Westerners. Ask a Thai person to describe holy basil and the first thing they'll say is hom, or "smells good." You'll notice that versions that people have cooked for themselves and their families, compared to those sold by street vendors, contain even more holy basil, which is relatively pricey in Thailand. That's one benefit of making it yourself -- you control the size of the handful. The other is being above the hot pan when you add that handful, the pleasure of being in a room overtaken by its scent.