Beef Tenderloin in Caramelized Sugar

Though you occasionally see this technique in other cuisines, I know of nowhere but Vietnam where caramelized sugar is used as the basis for a savory sauce in such a wide variety of dishes. You see it with pork, beef, shrimp, finfish, chicken, and even frog. You see it in fancy urban restaurants and in rural three-sided structures. Completed by plenty of onions and black pepper, the result is wickedly forceful, decidedly delicious, and, in the sauce's dark brown glossiness, downright gorgeous, an astonishing creation given the number of ingredients and the time it requires.
- 4 filets mignons, each at least 1 inch thick
- 1 cup sugar
- ½ cup nam pla, or to taste
- 1 large onion, sliced into half-moons
- 1 teaspoon black pepper, or more to taste
Instructions:
- Heat a 10-inch skillet over high heat, then brown the meat well on both sides; it won't take more than a minute or two per side. Turn off the heat and transfer the steaks to a plate.
- A minute later, add the sugar to the pan and turn the heat to medium. Cook, occasionally shaking the pan gently, until the sugar liquefies and begins to bubble. When the sugar is all liquid, cook for another minute or so, until it darkens; turn off the heat. Mix the nam pla with ½ cup water; carefully, and at arm's length, add the liquid and turn the heat to medium-high. Cook, stirring constantly, until the caramel melts into the liquid. Add the onion and cook, stirring occasionally, until it softens, about 5 minutes. Stir in any liquid that has accumulated around the meat.
- Stir in the black pepper and return the meat to the pan. Cook over medium heat, turning the meat once in a while, until it is done to your liking (5 to 8 minutes for medium-rare). Taste and adjust the seasoning, then serve, spooning a bit of the onion and sauce over each steak.