Seared Thai beef lettuce cups

Beef tenderloin, fat trimmed, cut into ½-1-1 ½-inch pieces	1 pound
Ginger, peeled, very finely minced	2 tablespoons
Garlic, minced	2 tablespoons
Lemongrass, white part only, very finely minced	2 tablespoons
Sugar	¼ cup
Fish sauce	3 tablespoons
Lime juice, freshly squeezed	3 tablespoons
Rice vinegar	2 tablespoons
Asian chili paste	2 teaspoons
Peanut oil	¼ cup + 3 tablespoons
Salt, kosher	1 teaspoon
Peanuts, salted	1/3 cup
Lime, cut into wedges	1
Cilantro sprigs
Romaine lettuce hearts	10 leaves

1. Combine the ginger, garlic, lemongrass, and sugar in a food processor; process for 1 minute.
2. Add the fish sauce, juice, vinegar, chili paste, oil, and salt; process for 1 minute.
3. Add three-fourths of the marinade with the beef in a Ziploc bag, mix well; refrigerate overnight.
4. Reserve remaining marinade.
5. Drain the meat, and discard the used marinade.
6. Heat a large, heavy saute pan or wok over high heat until very hot, almost smoking.
7. With the reserved marinade close at hand, add 1 tablespoon of oil until hot but not smoking.
8. Add half of the beef, and cook until well browned but still rare to medium-rare, about 4 minutes; let the beef get a nice color, but turn it frequently while cooking; transfer to a platter, and keep warm.
9. Cook the remaining beef, adding more oil, as needed; ensure the pan is very hot, and cook the beef quickly.
10. As soon as the last batch of beef is done, quickly add the reserved marinade to the hot pan.
11. Add the beef and heated marinate to the warmed platter.
12. Sprinkle with peanuts; garnish with lime wedges and cilantro sprigs.
13. Tuck lettuce cups around the edges, and serve immediately.

Recipe adapted from Sips & Apps by Kathy Casey.