Step 1

Bring a pot of water to boil over high heat. Place vermicelli noodles in the boiling water an remove from heat. Let sit until softened, 4 to 5 minutes. Drain using a colander and rinse under cold water. Drain away excess water, tossing noodles with oil if they stick together.

Step 2

Puree lemongrass, shallot, garlic, fish sauce, and sugar in a food processor. Place in a medium bowl or resealable bag; add steak and toss to coat. Let marinate at least 30 minutes, up to a day.

Step 3

Heat cooking oil in a pan over medium-high heat. Remove steak from marinade and sear in the hot pan, without stirring, until no longer pink, 3 to 4 minutes per side.

Step 4

Mix dressing ingredients together. Let chill until ready to use.

Step 5

Divide rice noodles between serving bowls. Top with 2 handfuls of veggies, flank steak, and beef. Drizzle peanut sauce over ingredients and top with fried shallots.