Cut the vegetables into thin matchsticks or slice thinly so they're easy to mix and pick up with chopsticks. Slice the onion into wedges. Finely chop the lemongrass, garlic, and shallot.

Marinate the beef with chicken bouillon powder, black pepper, and oyster sauce for 15 minutes.

Make scallion oil by heating chopped scallions with oil in a pan or microwave.

Roast the peanuts in a pan or microwave, then roughly crush them.

Sauté the garlic and lemongrass until fragrant and golden, then add the onion. Finally, add the beef and stir-fry just until it's medium rare. Turn off the heat and let the beef finish cooking in the residual heat of the pan.

Wash and chop the lettuce. Arrange all the ingredients on the table for self-serve. To eat, add everything to a bowl, pour the sweet and tangy fish sauce dressing over, toss, and enjoy!