Phat fai daeng literally means "fried with fire" and refers a style of flash-frying vegetables where the oil is ignited by the cooking flame, giving the dish a desireable "smoky" flavor. The most typical vegetables to be cooked this way are phak boong ("morning glory"--not the flower), phak khanaa ("Chinese broccoli"), and a Thai vegetable known as phak krachet. I make this dish almost every week; it's easy, nutritious and delicious.
An important element of this dish is the sauce. Here's what I use:
On the left is Heinz brand oyster sauce, and on the right, tao jiaow, a sauce of whole fermented soybeans. Some people will also use a touch of fish sauce or sii ew (Thai soy sauce), but I really like the simple combination of these two ingredients. It's essential to have your mise en place, the sauces and a bit of water, ready and easy to reach. This whole dish will take no more than about 1 1/2 minutes to make, so timing is essential.
Today I'm using young phak khanaa. I've taken the leaves and chopped them into largish pieces, and have halved the harder stalks (sorry, forgot to photograph this!). I usually soak them in cool water to crispen them up before frying.
In a mortar and pestle, grind up a healthy (or my case very healthy) amount of phrik khii noo (tiny Thai chilies) and a few cloves of garlic. Grind them together just enough to break them--you're not making a paste here. (Sometimes I like to throw a few peppercorns in at this step. This is a personal preference, definately not a Thai thing, but tastes good.) Set aside.
Heat a generous (4 Tbsps?) amount of cooking oil, and fry the smashed garlic and chilies over med-high heat for about 20 seconds, just long enough to make them "wilt":
Then turn your heat up as high as possible, add about 1 Tbsp of the tao jiaow (be careful, it's very salty), give a quick stir, add the veg, top with some oyster sauce, and a couple tablespoons of water. Now the fun starts: stir the mess up while tilting the pan to one side. If you've used enough oil it will ignite in a big fat beautiful flame:
Continue to do this several times during the cooking process to ensure that wonderful smoked flavor. Again, this should not take more than 1 minute, and you want the veggies to be just cooked, preferably still crispy and ever-so-slightly undercooked:
Done.