Make no mistake: This recipe barely approaches the complex flavors and even color in the classic, savory caramel sauce that shines up Vietnamese street food -- the bitterness of burnt sugar, the salty-smooth punch of soy and fish sauces, the aromatics of garlic and sometimes lemon grass.
But even the most basic nuoc mau, or sugar-water caramel, takes close attention and a while to prepare, and we've got just minutes to get on the table. So here, we are making a "light" version of the sauce that will enhance the natural sweetness of the fish, yet the overall taste is surprisingly piquant.
You can add green beans straight from the freezer, and they'll become crisp-tender by the time the fish is done. Thicker-cut cod fillets yield nice, meaty chunks in this dish, and they tend to fall apart less than pieces cut from thin fillets. But either will taste good! Once you get the technique down, feel free to try it with chunks of chicken or pork.
Touches of crushed red pepper flakes and fresh mint add the right amount of zip.
Serve over rice; to gild this particular lily, you could place a runny-yolk fried egg on top.